In majority (upto 90% to 95%) of people with hypertension, the cause cannot be determined; this is termed as essential or primary hypertension. Often a combination of genetic, lifestyle and environmental factors may play a role. In about 10% of  people with hypertension the specific cause can be determined; this is termed as secondary hypertension.

Primary Hypertension

Primary hypertension is usually seen in young adults and middle age (25-55 years). It’s uncommon before the age of 20 years. Several predisposing and precipitating factors may lead to hypertension.

The predisposing factors are the ones which are not within our control and therefore cannot be changed, these factors are known as non-modifiable risk factors.

  • Heredity:Children of parents with high blood pressure are at a greater risk of developing hypertension. The risk is higher if both the parents have high blood pressure.
  • Defect in sodium excretion: One of the functions of kidneys is to excrete excess sodium in the urine. Normally kidneys are able to do so but in some people the kidneys are unable to excrete the excess sodium leading to retention of sodium in the body. This in turn is responsible for raised blood pressure.
  • Age and Sex:  Blood pressure tend to rise with age in both men and women.Men are at a greater risk of developing hypertension than women at a younger age (below the age of 45 years). After menopause, women become more prone to heart disease (high blood pressure in particular).

The precipitating factors are the ones which are with in our control and hence can be changed. These factors are known as modifiable risk factors. If changed, they can reduce the risk of developing hypertension.

  • Obesity :It has been established that a weight within the ‘desirable range’ reduces the chances of hypertension considerably.
  • Cigarette smoking : Smoking tends to increase blood pressure.
  • Alcohol consumption : Alcohol consumption increases blood pressure, especially if the amount is more than 40g (i.e. 2 pegs) per day or if the person drinks in “binges” (bouts of drinking).
  • Sedentary lifestyle :It leads to obesity and increases the chances of hypertension . Aerobic exercises tend to lower blood pressure in previously sedentary individuals.
  • Diabetes :People with diabetes are more prone to develop hypertension and its complications. This is more so, if the diabetes is poorly controlled.
  • Salt Intake : High salt intake raises the blood pressure in some people. Consuming more than 7g (about one and a half teaspoon) of salt in a day is said to be high.
  • Fatty foods :Consuming a diet rich in meat (especially red meat) and dairy products (such as cheese, ghee, full cream milk) raises the blood pressure as well as the cholesterol levels.
  • Other dietary factors : Diet low in potassium, calcium and magnesium also increases the risk.
  • Stress :No studies till date have proven stress to be cause of hypertension but it is believed to aggravate already existing disease.

At times, a transient rise in blood pressure is noted in a few people when they visit a doctor or hospital; this is termed as “white coat” hypertension. These people may not need treatment then but are prone to frank hypertension in later life