Blood pressure is determined by two things: the amount of blood the heart pumps and how hard it is for the blood to move through the arteries. The more blood the heart pumps and the narrower the arteries, the higher the blood pressure.
There are two main types of high blood pressure.
Primary hypertension, also called essential hypertension
For most adults, there’s no identifiable cause of high blood pressure. This type of high blood pressure is called primary hypertension or essential hypertension. It tends to develop gradually over many years. Plaque buildup in the arteries, called atherosclerosis, increases the risk of high blood pressure.
Secondary hypertension
This type of high blood pressure is caused by an underlying condition. It tends to appear suddenly and cause higher blood pressure than does primary hypertension. Conditions and medicines that can lead to secondary hypertension include:
Adrenal gland tumors
Blood vessel problems present at birth, also called congenital heart defects
Cough and cold medicines, some pain relievers, birth control pills, and other prescription drugs
Illegal drugs, such as cocaine and amphetamines
Kidney disease
Obstructive sleep apnea
Thyroid problems
Sometimes just getting a health checkup causes blood pressure to increase. This is called white coat hypertension.