There are two types of hypertension:
- primary (essential) hypertension: it accounts for over 95% of all cases of hypertension. It tends to develop gradually over the years; it affects adults and it has no known cause.
- Secondary hypertension: this form is relatively rare; sometimes, it can disappear when its cause is eliminated. People under 20 or above 50 years old are usually affected. Secondary hypertension usually appears all of a sudden, causing higher pressure values than those of primary hypertension. It can be caused by multiple conditions, such as: renal diseases, adrenal gland cancer, birth defects affecting blood vessels, medication (birth control pill, decongestants, painkillers), and drugs (cocaine, amphetamine).
Hypertension is more common among adults, although children can also be affected because of kidney or heart-related conditions. Unhealthy life habits, such as an unhealthy diet and a lack of exercise, can contribute to the development of hypertension.