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