Investigations to be done in patients of hypertension
The aim of general investigations in hypertension is to screen for secondary causes and complications and to evaluate concomitant risk factors for atherosclerosis.
Urinalysis
Urine strip testing may reveal blood and protein, suggestive of renal disease. Urine microscopy is necessary to confirm the presence of red blood cells and also casts.
Urea and electrolytes
Urea and creatinine may be elevated with renal failure, and low serum potassium levels in untreated patients may be due to Conn's syndrome.
Blood glucose
Plasma glucose is performed to screen for diabetes as it is associated with atherosclerosis, renal vascular disease and nephropathy. All of these may contribute to hypertension. Moreover, causes of secondary hypertension such as Cushing's syndrome, acromegaly and phaeochromocytoma are associated with hyperglycaemia.
Serum cholesterol
Serum cholesterol screening should be performed as it is an additional risk factor for atherosclerosis and may require treatment for the prevention of cerebrovascular and ischaemic heart disease.
Electrocardiogram
A 12 lead ECG is required as a baseline investigation and to screen for left ventricular hypertrophy, a complication of hypertension.
Specific investigations
Specific investigations are usually tailored to suspected secondary causes. Relevant investigations for phaeochromocytoma , Cushing's syndrome , Conn's syndrome , coarctation of the aorta and renal artery stenosis in selected patients depending on the clinical judgment .
Renal ultrasound
Renal ultrasound is a good screening investigation for hypertensive patients when the suspected underlying cause is renal disease. It is best at detecting structural disorders such as polycystic kidney disease and renal artery stenosis.
Treatment of High Blood Pressure or, Hypertension:
Apart from blood pressure lowering, an important aspect of the management of hypertension encompasses modification of cardiovascular risk.
Lifestyle and risk factor modification
Weight loss towards ideal weight, regular exercise, limiting alcohol consumption, reduced salt intake and increased fruit and vegetable intake have been proven in clinical trials to reduce blood pressure and may obviate the need for pharmacological therapy for hypertension. This advice should be offered to all patients and is best supplemented with written information.
Low Dose Aspirin:
Aspirin reduces major cardiovascular events in hypertensive patients and should be prescribed for primary prevention in patients aged 50 or more with satisfactory control of blood pressure and those with target organ damage, diabetes or a 10-year coronary risk of more than 15%.
Statin to lower cholesterol
Cholesterol lowering therapy is recommended for hypertensive patients when serum cholesterol is more than 5.0 mmol/L and 10-year coronary risk is more than 30%.
Medical management
Antihypertensive medication
Each Anti hypertensive drug class has specific indications and contraindications. Click here to see the table. however, when these circumstances do not apply, the drug that has been backed by the most evidence is the thiazide diuretic, and this should be the initial agent of choice for the treatment of hypertension.
Each drug should be allowed 4 weeks before the response is assessed. The dose of each drug (except thiazide diuretics) should be increased accordingly if satisfactory control (less than 140/85 mmHg) is not achieved
If the first drug is well tolerated but the response is small, substitution with another drug is appropriate when hypertension is mild and uncomplicated. However, in severe or complicated hypertension it is safer to add drugs stepwise until blood pressure control is attained. Drug combinations are best tailored to the individual.
Prognosis of Hypertension
Death from hypertension relates primarily to the increased risk of ischaemic heart disease and stroke. The risk of premature death increases with blood pressure and age. Each 20 mmHg increase in systolic (or 10 mmHg increase in diastolic) pressure increases the risk of death by coronary heart disease or stroke approximately 2-fold in patients aged 40-69 years, and approximately 1.5-fold in patients aged 70-89 years
Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension
Showing posts with label Hypertension. Show all posts
Showing posts with label Hypertension. Show all posts
Saturday, April 25, 2009
Hypertension - Causes and Symptoms
Systemic Hypertension or High Blood pressure
Hypertension is a very common disease in developed countries and is a growing problem in developing countries. The overall prevalence in Europe is 44 000 per 100 000 (that is 44% of the entire population) and both sexes are affected equally. The prevalence increases with age from 27% in 35-44-year-olds to 78% in those aged between 65 and 74 years.
Causes of high blood pressure
An underlying cause is established in less than 10% and most patients will be classified with essential hypertension. Pathological changes associated with chronic sustained hypertension are hyaline and hyperplastic arteriolosclerosis.
Sometimes these underlying diseases cause hypertension-
Renal or Kidney diseases causing high blood pressure
Renal parenchymal diseases (glomerulonephritis)
Renal artery stenosis
Chronic pyelonephritis
Polycystic kidney disease
Connective tissue disease (systemic sclerosis)
Diabetic nephropathy
Endocrine diseases causing high blood pressure
Adrenal
Conn's syndrome
Phaeochromocytoma
Cushing's syndrome
Acromegaly
Drugs diseases causing high blood pressure
Glucocorticoids (corticosteroids)
Mineralocorticoids (liquorice)
Monoamine oxidase inhibitors and tyramine
Sympathomimetic agents (salbutamol)
Cardiovascular diseases causing high blood pressure
Coarctation of the aorta
Usual complications of high blood pressure:
Hypertension is a major risk factor for atherosclerosis. Complications involve the eye (hypertensive and arteriosclerotic retinopathy), heart (coronary heart disease, heart failure), brain (stroke) and kidney (nephrosclerosis and hypertensive renal disease).
Symptoms of high blood pressure or, hypertension:
Uncomplicated essential hypertension is asymptomatic and is identified during the course of routine physical examination. Patients with secondary hypertension, however, may complain of symptoms from the underlying disorder. A detailed drug history should reveal any offending drug that can cause hypertension.
In addition to establishing the diagnosis of hypertension (sustained rise in blood pressure above 140/90 mmHg on three or more readings, each at least a week apart), a detailed clinical assessment will also screen for any evidence of complications and attempt to ascertain any underlying cause as mentioned earlier in the article.
Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension
Hypertension is a very common disease in developed countries and is a growing problem in developing countries. The overall prevalence in Europe is 44 000 per 100 000 (that is 44% of the entire population) and both sexes are affected equally. The prevalence increases with age from 27% in 35-44-year-olds to 78% in those aged between 65 and 74 years.
Causes of high blood pressure
An underlying cause is established in less than 10% and most patients will be classified with essential hypertension. Pathological changes associated with chronic sustained hypertension are hyaline and hyperplastic arteriolosclerosis.
Sometimes these underlying diseases cause hypertension-
Renal or Kidney diseases causing high blood pressure
Renal parenchymal diseases (glomerulonephritis)
Renal artery stenosis
Chronic pyelonephritis
Polycystic kidney disease
Connective tissue disease (systemic sclerosis)
Diabetic nephropathy
Endocrine diseases causing high blood pressure
Adrenal
Conn's syndrome
Phaeochromocytoma
Cushing's syndrome
Acromegaly
Drugs diseases causing high blood pressure
Glucocorticoids (corticosteroids)
Mineralocorticoids (liquorice)
Monoamine oxidase inhibitors and tyramine
Sympathomimetic agents (salbutamol)
Cardiovascular diseases causing high blood pressure
Coarctation of the aorta
Usual complications of high blood pressure:
Hypertension is a major risk factor for atherosclerosis. Complications involve the eye (hypertensive and arteriosclerotic retinopathy), heart (coronary heart disease, heart failure), brain (stroke) and kidney (nephrosclerosis and hypertensive renal disease).
Symptoms of high blood pressure or, hypertension:
Uncomplicated essential hypertension is asymptomatic and is identified during the course of routine physical examination. Patients with secondary hypertension, however, may complain of symptoms from the underlying disorder. A detailed drug history should reveal any offending drug that can cause hypertension.
In addition to establishing the diagnosis of hypertension (sustained rise in blood pressure above 140/90 mmHg on three or more readings, each at least a week apart), a detailed clinical assessment will also screen for any evidence of complications and attempt to ascertain any underlying cause as mentioned earlier in the article.
Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension
Choice of Medication in Hypertension
Choice of drug therapy for hypertension |
| Indication | Contraindications | |||
| Compelling | Possible | Possible | Compelling | |
| Prostatism | Dyslipidaemia | Postural hypotension | Urinary incontinence | |
| Heart failure | Chronic renal disease | Renal impairment | Pregnancy | |
| Left ventricular dysfunction | Type II diabetic nephropathy | Peripheral vascular disease | Renovascular disease | |
| Type I diabetic nephropathy | | | | |
| Cough induced by ACE inhibitor | Heart failure
| Peripheral vascular disease | Pregnancy
| |
| Myocardial infarction
| Heart failure | Heart failure
| Asthma or chronic obstructive pulmonary disease
| |
| Isolated systolic hypertension in elderly patients | Angina
| - | - | |
| Angina | Myocardial infarction | Combination with β-blockade | Heart block
| |
| Elderly patients | - | Dyslipidaemia | Gout | |
Causes and Symptoms of Hypertension
Investigations and Treatment of Hypertension
Choice of drug therapy in hypertension
Tuesday, February 10, 2009
Frequently asked questions (FAQ) about hypertension
Q . Is it normal to rise the BP with age?
A. It is the common belief but not true. All the studies shown previously that blood pressure rises with age. But none of the studies took into consideration of the lifestyle of the volunteers for the study. Now with present study with a group with proper lifestyle, no increase of BP with age is found. Dietary restriction, low salt diet and with healthy life styles BP should remain the same with your age, despite of the fact the elasticity of the blood vessels are lessened.
Q. Is hypertension is a hereditary disease?
A. Obesity and hypertension tend to run in families. These are not genetic diseases but a particular set of genes may produce a predilection to these diseases. A person with such predilection and unhealthy lifestyle will develop hypertension very early in life; and on the other hand with healthy habits this person may develop hypertension in mild form or, not at all.
Another very important aspect on higher incidence of hypertension is found in low birth weight babies, particularly so if they become obese in childhood. It is very essential to be careful about diet and stringent medical supervision in the expectant period of the future mother. Incidence of low birth weight babies can be minimized and do take care of your babies’ food habit. Childhood obesity has intimate relationship with hypertension and diabetes in later life.
Q I have hypertension – should I stop taking salt?
A. It is a punishment to have a salt free diet continuously. Though salt sensitive hypertension responds favorably with no salt diet but not all form of hypertension will respond. 60% patients do well with restricted salt intake (means no extra salt other than what is there in normal cooking); so it is standard practice to prescribe salt restricted diet for hypertension.
Q. What happens when there is high BP in pregnancy?
A. Two conditions may present:
1. She was hypertensive before pregnancy and now conceived. In this case the chance of complications of pregnancies and BP can rise further. They should be dealt by the specialists in this field. The dose of the drugs or, the drugs itself may need to be changed for the benefit of both mother and the babies.
2. She was normal and develops hypertension following pregnancy. This may occur in mild. Moderate and severe form. Cause is not yet known and also known as pregnancy induced hypertension or PIH. Previously it is used to be called as pre eclampsia or, toxaemia of pregnancy. The condition is treated by drugs and close supervision and managed according to the severity. Nowadays with modern medication on most of these cases both mother and babies are having favorable outcome. In most cases blood pressure returns to normal 6 weeks after delivery.
Q. Is there any relation of birth control pills (Oral Contraceptive Pill) with high blood pressure?
A. The problem today is much less with very low dose oral pills. Usually the women, who are susceptible to hypertension for their family history, obesity, wrong lifestyles may develop hypertension with pills. This is a warning sign. Though the BP will come down with stopping of pill she should modify her lifestyle to prevent hypertension in later life.
This article is republished in India Study Channel
A. It is the common belief but not true. All the studies shown previously that blood pressure rises with age. But none of the studies took into consideration of the lifestyle of the volunteers for the study. Now with present study with a group with proper lifestyle, no increase of BP with age is found. Dietary restriction, low salt diet and with healthy life styles BP should remain the same with your age, despite of the fact the elasticity of the blood vessels are lessened.
Q. Is hypertension is a hereditary disease?
A. Obesity and hypertension tend to run in families. These are not genetic diseases but a particular set of genes may produce a predilection to these diseases. A person with such predilection and unhealthy lifestyle will develop hypertension very early in life; and on the other hand with healthy habits this person may develop hypertension in mild form or, not at all.
Another very important aspect on higher incidence of hypertension is found in low birth weight babies, particularly so if they become obese in childhood. It is very essential to be careful about diet and stringent medical supervision in the expectant period of the future mother. Incidence of low birth weight babies can be minimized and do take care of your babies’ food habit. Childhood obesity has intimate relationship with hypertension and diabetes in later life.
Q I have hypertension – should I stop taking salt?
A. It is a punishment to have a salt free diet continuously. Though salt sensitive hypertension responds favorably with no salt diet but not all form of hypertension will respond. 60% patients do well with restricted salt intake (means no extra salt other than what is there in normal cooking); so it is standard practice to prescribe salt restricted diet for hypertension.
Q. What happens when there is high BP in pregnancy?
A. Two conditions may present:
1. She was hypertensive before pregnancy and now conceived. In this case the chance of complications of pregnancies and BP can rise further. They should be dealt by the specialists in this field. The dose of the drugs or, the drugs itself may need to be changed for the benefit of both mother and the babies.
2. She was normal and develops hypertension following pregnancy. This may occur in mild. Moderate and severe form. Cause is not yet known and also known as pregnancy induced hypertension or PIH. Previously it is used to be called as pre eclampsia or, toxaemia of pregnancy. The condition is treated by drugs and close supervision and managed according to the severity. Nowadays with modern medication on most of these cases both mother and babies are having favorable outcome. In most cases blood pressure returns to normal 6 weeks after delivery.
Q. Is there any relation of birth control pills (Oral Contraceptive Pill) with high blood pressure?
A. The problem today is much less with very low dose oral pills. Usually the women, who are susceptible to hypertension for their family history, obesity, wrong lifestyles may develop hypertension with pills. This is a warning sign. Though the BP will come down with stopping of pill she should modify her lifestyle to prevent hypertension in later life.
This article is republished in India Study Channel
Managing Hypertension
Once the diagnosis of hypertension is made few laboratory investigations are mandatory. These tests may come out as normal, but this gives an important baseline guideline for managing hypertension in future. The test are directed to the organs, the high BP commonly affects. These following tests are done and should be repeated every year.
Basic investigations required for a patient with hypertension:
1. Electrocardiogram or, ECG to know the condition of the heart
2. Echocardiography, to see the heart’s function if ECG is abnormal
3. Serum Cholesterol and its fractions, triglycerides – their relevance with heart attack and stroke and diabetes.
4. Blood sugar levels - Hypertension is frequently associated with diabetes.
5. Serum urea, creatinine and electrolytes (sodium, potassium, and chlorides) – These will tell the status of kidney.
6. A routine urine examination – will also tell about the kidney status.
Treating the hypertension:
Hypertension treatment has clearly 2 factors.
1. Lowering of blood pressure by medicines
2. Lifestyle modifications.
Medicines are essential to tide over the immediate crisis and in most of the cases has to be continued for life long. But this is not the ultimate solution. Unless lifestyle modification is done, the drugs may not work properly and much higher doses with all their side effects may be required.
Blood pressure lowering drugs acts in many ways. Some relax the vessel wall; some excretes excess water and thus reduce the load. Drugs has definite time periods of working. Some works 12 hrs. some 24 hrs. The doses are to be given accordingly. The doctor, who is treating you is the best judge for the drugs, which will suite you. He might combine different drugs, fortunately there are many to chose from nowadays, to get better results and lesser side effects. You may be wondered why so many drugs while you have no symptoms at all! Hypertension is rightly named “silent killer”. Even if the person is having no symptoms; the major organs get affected slowly and suddenly produces disastrous outcome. So never ignore the treatment, even if you have no symptoms.
Lifestyle modifications must be given equal importance as the drugs. Wrong dietary habits, no exercise, smoking, excessive alcohol intake, mental stress with no relaxation are all common bad habits found in obese, diabetic and hypertesives. These trio are the major killer these days. They are very much interrelated and thrive on our bad habits.
Changing habits is difficult to start with but, once you get the beautiful feelings after getting rid of them, you will never look back to them. Life is beautiful. Don’t ruin it.
This article is republished in India Study Channel
Basic investigations required for a patient with hypertension:
1. Electrocardiogram or, ECG to know the condition of the heart
2. Echocardiography, to see the heart’s function if ECG is abnormal
3. Serum Cholesterol and its fractions, triglycerides – their relevance with heart attack and stroke and diabetes.
4. Blood sugar levels - Hypertension is frequently associated with diabetes.
5. Serum urea, creatinine and electrolytes (sodium, potassium, and chlorides) – These will tell the status of kidney.
6. A routine urine examination – will also tell about the kidney status.
Treating the hypertension:
Hypertension treatment has clearly 2 factors.
1. Lowering of blood pressure by medicines
2. Lifestyle modifications.
Medicines are essential to tide over the immediate crisis and in most of the cases has to be continued for life long. But this is not the ultimate solution. Unless lifestyle modification is done, the drugs may not work properly and much higher doses with all their side effects may be required.
Blood pressure lowering drugs acts in many ways. Some relax the vessel wall; some excretes excess water and thus reduce the load. Drugs has definite time periods of working. Some works 12 hrs. some 24 hrs. The doses are to be given accordingly. The doctor, who is treating you is the best judge for the drugs, which will suite you. He might combine different drugs, fortunately there are many to chose from nowadays, to get better results and lesser side effects. You may be wondered why so many drugs while you have no symptoms at all! Hypertension is rightly named “silent killer”. Even if the person is having no symptoms; the major organs get affected slowly and suddenly produces disastrous outcome. So never ignore the treatment, even if you have no symptoms.
Lifestyle modifications must be given equal importance as the drugs. Wrong dietary habits, no exercise, smoking, excessive alcohol intake, mental stress with no relaxation are all common bad habits found in obese, diabetic and hypertesives. These trio are the major killer these days. They are very much interrelated and thrive on our bad habits.
Changing habits is difficult to start with but, once you get the beautiful feelings after getting rid of them, you will never look back to them. Life is beautiful. Don’t ruin it.
This article is republished in India Study Channel
Sunday, February 8, 2009
Complications of having high BP (Hypertension) and they can be prevented
Complications of having high BP (Hypertension) and they can be prevented:
Blood pressure itself is a symptom less disease but when long standing it affects major organs and causing dreadful complications. The main organs prone to get affected by high BP are heart, kidneys, eyes and kidneys.
How hypertension affects heart?
If the resistance of the pipes increases pump has to work hard to pump water through it. Same is with the heart. The left ventricle, the prime motor works hard and gets enlarged. Heart needs more energy to work hard and so more oxygen. Ultimately supply becomes less than the demand and this causes chest pain, popularly known as angina. When this aggravates more some portion of the heart may die because lack of oxygen or, blood flow and myocardial infarction is the result. When left ventricle cannot cope up with the work load it fails and that leads to heart failure or, Left ventricular failure.
How hypertension can affect the brain?
Stroke – a term used which means loss of some functions of the brain suddenly. This occurs due to sudden blockade or rupture of the blood vessels in the brain. According to the site of assault paralysis, loss of speech, loss of vision, unconsciousness occurs. Hypertension is one of the single important cause of stroke. So, this dreadful situation can be averted by treating hypertension promptly.
How hypertension can affect eyes?
Eyes are extension of the brain. Same vascular assault, which occurs in brain can also occur in eyes. This lead to retinal hemorrhage and sudden blindness. The condition can be prevented by diagnosing and treating hypertension promptly.
How hypertension can affect kidneys?
The relation between kidney and blood pressure is already discussed. A significant number of hypertensive persons ultimately develop kidney disease due to their high BP and die of renal failure. Regular medical checkups and investigations to check renal function at reasonable interval is very essential for all hypertensive persons.
This article is republished in India Study Channel
Blood pressure itself is a symptom less disease but when long standing it affects major organs and causing dreadful complications. The main organs prone to get affected by high BP are heart, kidneys, eyes and kidneys.
How hypertension affects heart?
If the resistance of the pipes increases pump has to work hard to pump water through it. Same is with the heart. The left ventricle, the prime motor works hard and gets enlarged. Heart needs more energy to work hard and so more oxygen. Ultimately supply becomes less than the demand and this causes chest pain, popularly known as angina. When this aggravates more some portion of the heart may die because lack of oxygen or, blood flow and myocardial infarction is the result. When left ventricle cannot cope up with the work load it fails and that leads to heart failure or, Left ventricular failure.
How hypertension can affect the brain?
Stroke – a term used which means loss of some functions of the brain suddenly. This occurs due to sudden blockade or rupture of the blood vessels in the brain. According to the site of assault paralysis, loss of speech, loss of vision, unconsciousness occurs. Hypertension is one of the single important cause of stroke. So, this dreadful situation can be averted by treating hypertension promptly.
How hypertension can affect eyes?
Eyes are extension of the brain. Same vascular assault, which occurs in brain can also occur in eyes. This lead to retinal hemorrhage and sudden blindness. The condition can be prevented by diagnosing and treating hypertension promptly.
How hypertension can affect kidneys?
The relation between kidney and blood pressure is already discussed. A significant number of hypertensive persons ultimately develop kidney disease due to their high BP and die of renal failure. Regular medical checkups and investigations to check renal function at reasonable interval is very essential for all hypertensive persons.
This article is republished in India Study Channel
Thursday, January 29, 2009
When the blood pressure is considered abnormal and what are the symptoms?
How high the BP is abnormal?
120 mm of Hg systolic and 80 mm Hg diastolic is considered normal BP. But the blood pressure of a person is not a single entity. Throughout the day, depending on our stress, mood, physical activities it varies. So a single measurement above 120/ 80 cannot be considered abnormal and person cannot be called as hypertensive. If the reading continues to be high repeatedly even when he is relaxed then the person is considered as hypertensive.
For practical purposes systolic pressure >120 & <138>80 & <> 140/ 90 is treated actively.
Previously much importance was not given to raised systolic BP, and was considered due to stress or, anxiety. Nowadays persistently high systolic BP is considered as a disease entity and treated. Labile hypertension is another entity where a person’s BP is found mild to moderately elevated at some visits and normal at other visits. They are very likely to to step in the persistent hypertension club sooner or, later.
What are the symptoms of hypertension or high blood pressure?
Hypertension is also called rightly as “Silent Killer”. Most of the time it develops with no symptom at all. It steady increases without warning and develop symptoms when it has already damaged many organs beyond repair. The symptoms when occur, the hypertension is then severe enough. Headache is a well known symptom, mainly felt at the back of the head, particularly worse while waking up in the morning and gradually become less as the day progresses. Long standing hypertension, when affect the heart function may cause shortness of breath on exertion and swelling around the ankle. Easy tiredness, dizziness, low sexual potential, palpitations are the symptoms in severe hypertension.
Organ specific symptoms are also very late to develop. Effect on the vessels of nose give rise to nose bleeding or epistaxis, Urinary tract to blood in urine, brain to sudden black outs.
As these are very late to develop regular check up of blood pressure is recommended. After the age of 30 blood pressure should be checked every alternate years and after 40 each year.
This article is republished in India Study Channel
120 mm of Hg systolic and 80 mm Hg diastolic is considered normal BP. But the blood pressure of a person is not a single entity. Throughout the day, depending on our stress, mood, physical activities it varies. So a single measurement above 120/ 80 cannot be considered abnormal and person cannot be called as hypertensive. If the reading continues to be high repeatedly even when he is relaxed then the person is considered as hypertensive.
For practical purposes systolic pressure >120 & <138>80 & <> 140/ 90 is treated actively.
Previously much importance was not given to raised systolic BP, and was considered due to stress or, anxiety. Nowadays persistently high systolic BP is considered as a disease entity and treated. Labile hypertension is another entity where a person’s BP is found mild to moderately elevated at some visits and normal at other visits. They are very likely to to step in the persistent hypertension club sooner or, later.
What are the symptoms of hypertension or high blood pressure?
Hypertension is also called rightly as “Silent Killer”. Most of the time it develops with no symptom at all. It steady increases without warning and develop symptoms when it has already damaged many organs beyond repair. The symptoms when occur, the hypertension is then severe enough. Headache is a well known symptom, mainly felt at the back of the head, particularly worse while waking up in the morning and gradually become less as the day progresses. Long standing hypertension, when affect the heart function may cause shortness of breath on exertion and swelling around the ankle. Easy tiredness, dizziness, low sexual potential, palpitations are the symptoms in severe hypertension.
Organ specific symptoms are also very late to develop. Effect on the vessels of nose give rise to nose bleeding or epistaxis, Urinary tract to blood in urine, brain to sudden black outs.
As these are very late to develop regular check up of blood pressure is recommended. After the age of 30 blood pressure should be checked every alternate years and after 40 each year.
This article is republished in India Study Channel
Common Causes ( Mechanism) of High Blood Pressure
As already mentioned in the previous post it is understood that elasticity of the arteries plays an important role in maintaining the BP. Factors which reduce the elasticity of the blood vessels, which naturally occurs with age raise the BP.
Apart from the elasticity, the diameter of the arteries is also important. The lumen of the arteries can become smaller by two important factors.
i) Deposition of fat in the wall, thereby reducing the lumen and raise the BP gradually
ii) Spasm of the muscles of the arteries, may cause sudden rise of BP
iii) The above two factors may act simultaneously some times – a double trouble!
The volume and quality of the blood is also important to maintain the blood pressure. If by any chance, the volume is low (blood loss) or quality is poor (anaemia), heart has to pump more frequently and vigorously to provide adequate oxygen and nutrition to the tissues. This in turn can raise the BP. Thus in case of sudden bleeding initial body response is a little raised BP preceding eventual fall.
Brain plays an important role to maintain the blood pressure. From the brain by different hormonal messenger the blood flow and the pressure of different arteries are controlled as per requirement. It has both good and bad effect for us. Good effect is – When you are ready for a nice lunch, you brain increases the blood flow to your stomach to digest your food. Similarly when you are annoyed or shouting the unwanted shoot up of BP is a detrimental effect caused by the brain.
Kidneys are another important organ which control our BP. They control the salt and water balance in our body by different hormonal mechanisms. They decide how much water and salt to be excreted in the urine and how thirsty we will feel? With generalized narrowing of the blood vessels due to deposition of fats kidney vessels are also affected and raise the blood pressure by affecting their function. Primary kidney related disease of the kidneys also elevate the blood pressure.
This article is republished in India Study Channel
Apart from the elasticity, the diameter of the arteries is also important. The lumen of the arteries can become smaller by two important factors.
i) Deposition of fat in the wall, thereby reducing the lumen and raise the BP gradually
ii) Spasm of the muscles of the arteries, may cause sudden rise of BP
iii) The above two factors may act simultaneously some times – a double trouble!
The volume and quality of the blood is also important to maintain the blood pressure. If by any chance, the volume is low (blood loss) or quality is poor (anaemia), heart has to pump more frequently and vigorously to provide adequate oxygen and nutrition to the tissues. This in turn can raise the BP. Thus in case of sudden bleeding initial body response is a little raised BP preceding eventual fall.
Brain plays an important role to maintain the blood pressure. From the brain by different hormonal messenger the blood flow and the pressure of different arteries are controlled as per requirement. It has both good and bad effect for us. Good effect is – When you are ready for a nice lunch, you brain increases the blood flow to your stomach to digest your food. Similarly when you are annoyed or shouting the unwanted shoot up of BP is a detrimental effect caused by the brain.
Kidneys are another important organ which control our BP. They control the salt and water balance in our body by different hormonal mechanisms. They decide how much water and salt to be excreted in the urine and how thirsty we will feel? With generalized narrowing of the blood vessels due to deposition of fats kidney vessels are also affected and raise the blood pressure by affecting their function. Primary kidney related disease of the kidneys also elevate the blood pressure.
This article is republished in India Study Channel
What Is Blood Pressure?
Consider heart as water pump and blood vessels as net work of elastic rubber pipe networks. This will help you to understand what the blood pressure really means. It can be easily understood while the pump is pumping the maximum pressure is exerted on the wall of the tube, which is nearer to the pump. The furthest part has least pressure. The pressure also depends on the caliber of the tube,which is nearer to the pump.
The furthest part has least pressure. The pressure also depends on the caliber of the tube. Our heart has four chambers. Left ventricle actually pumps blood to the circulatory network at an average rate of 72/ min. The pump of heart works in different way than the water pump. It does not pump continuously. While beating at a rate of 75 per minute, it beats every 0.8 seconds. In this 0.8 sec, it pumps for 0.3 sec and rest 0.5 sec it relaxes to receive blood for pumping. Now you can understand the pressure in the blood vessels are not always equal. It is highest when the heart is pumping and lowest when it is receiving blood. Blood comes out through one large arched tube known as arch of aorta and then through divisions it comes to the arteries, which again divide and subdivide to arterioles and capillaries. Pressure is not equal in all these branches. For clinical purpose we measure blood pressure in arteries, precisely in the brachial artery in our arms.
You have noticed while doctors are telling the blood pressure, they are telling two values one is systolic that is on the higher side and one is diastolic that is on the lower side. The Systolic is the highest pressure exerted by blood on the wall of the arteries during contraction of the ventricle or systole and Diastolic is the lowest pressure exerted during relaxation or diastole. Normally the systolic blood pressure remains 120mm of mercury and the diastolic at 80 mm of mercury.
You may be wondered why the difference is so low and while the heart is relaxing why the lowest pressure is not 0! It is due to the elasticity of the artery which recoils during relaxation and expands during contraction and keeps the blood pressure to this limit, which is so essential for maintaining the perfusion of oxygen to the tissues.
If elasticity of the arteries is reduced it will increase the peak pressure and the gap between systolic and diastolic pressure will widen.
There are many other factors which maintain the normal blood pressure of our body. Few important factors are volume of blood, quality of blood, function of other organs like brain, kidney and other hormones. Altogether a complex phenomenon is maintaining the blood pressure, the pressure required to exchange nutrition and oxygen to the tissues.
This article is republished in India Study Channel
The furthest part has least pressure. The pressure also depends on the caliber of the tube. Our heart has four chambers. Left ventricle actually pumps blood to the circulatory network at an average rate of 72/ min. The pump of heart works in different way than the water pump. It does not pump continuously. While beating at a rate of 75 per minute, it beats every 0.8 seconds. In this 0.8 sec, it pumps for 0.3 sec and rest 0.5 sec it relaxes to receive blood for pumping. Now you can understand the pressure in the blood vessels are not always equal. It is highest when the heart is pumping and lowest when it is receiving blood. Blood comes out through one large arched tube known as arch of aorta and then through divisions it comes to the arteries, which again divide and subdivide to arterioles and capillaries. Pressure is not equal in all these branches. For clinical purpose we measure blood pressure in arteries, precisely in the brachial artery in our arms.
You have noticed while doctors are telling the blood pressure, they are telling two values one is systolic that is on the higher side and one is diastolic that is on the lower side. The Systolic is the highest pressure exerted by blood on the wall of the arteries during contraction of the ventricle or systole and Diastolic is the lowest pressure exerted during relaxation or diastole. Normally the systolic blood pressure remains 120mm of mercury and the diastolic at 80 mm of mercury.
You may be wondered why the difference is so low and while the heart is relaxing why the lowest pressure is not 0! It is due to the elasticity of the artery which recoils during relaxation and expands during contraction and keeps the blood pressure to this limit, which is so essential for maintaining the perfusion of oxygen to the tissues.
If elasticity of the arteries is reduced it will increase the peak pressure and the gap between systolic and diastolic pressure will widen.
There are many other factors which maintain the normal blood pressure of our body. Few important factors are volume of blood, quality of blood, function of other organs like brain, kidney and other hormones. Altogether a complex phenomenon is maintaining the blood pressure, the pressure required to exchange nutrition and oxygen to the tissues.
This article is republished in India Study Channel
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