What causes high blood pressure (hypertension)?

Diana Meeks
Diana Meeks on behalf of Sigma Nursing
Family Practitioner

There are two types of hypertension: primary and secondary. Primary hypertension develops slowly over time, and the reasons for this are still unknown. Most cases of hypertension (about 90 percent) fall into this category. Secondary hypertension is hypertension that is caused by another condition, such as kidney disease or adrenal/hormonal disorders, or by the use of some medications. Secondary hypertension tends to develop more quickly.

Tests can be done to find out if there is an underlying medical condition causing your hypertension. Your doctor will give you a thorough physical examination to detect any problems in your abdomen, kidneys and eyes, as conditions in these areas sometimes cause hypertension. Urinalysis is used to check for kidney problems. Blood tests may be done to check levels of potassium, sodium and red blood cells. Electrocardiography can detect any changes to or weaknesses in your heart.

High blood pressure (hypertension) affects an estimated 67 million Americans. In most cases, the causes of high blood pressure are not known. However, some things may increase your risk of developing high blood pressure. These include:

  • Heredity: High blood pressure tends to run in families.
  • Race: Black people have high blood pressure more often and more severely than whites.
  • Age: The tendency to develop high blood pressure increases as you age.
  • Obesity: People who are overweight have a greater chance of developing high blood pressure.
  • Lack of exercise: An inactive lifestyle may contribute to being overweight, which is a risk factor for high blood pressure.
  • Excessive alcohol use: Drinking excessive amounts of alcohol can increase blood pressure.
  • Too much dietary salt: Heavy use of salt can increase blood pressure.
  • Oral contraceptives: Women who take the pill have an increased chance of developing high blood pressure, especially if they also smoke.
  • Other diseases: Having chronic kidney disease increases your chance of developing high blood pressure.

High blood pressure is much less common in children than adults. Regular blood pressure checkups should begin during childhood and continue throughout life.

The 90 to 95 percent of hypertension cases in which the cause can't be determined are called essential or primary hypertension cases. Hypertension may also be a symptom of an identified problem (see below) that generally corrects itself when the identified cause is corrected. This type of high blood pressure is called secondary hypertension. Possible causes of secondary hypertension include:

  • renal artery stenosis (narrowing of the arteries leading to your kidneys)
  • adrenal gland disease (Cushing's disease) or adrenal tumors
  • kidney disease
  • preeclampsia (hypertension and increased urine protein levels sometimes caused by pregnancy)
  • thyroid disease
  • a large intake of licorice root extract (equivalent to 25 to 40 licorice candies a day for several years)

Other factors affecting blood pressure include:

  • use of birth control pills
  • psychologic stress
  • severe pain
  • drug or alcohol withdrawal
  • use of amphetamines, cocaine or other stimulants
  • Use of steroids
  • overuse of nicotine nasal sprays, gum, patches and lozenges designed to help smokers kick the habit
  • sleep apnea

Continue Learning about Hypertension

how does sleep affect blood pressure ?
Move the alarm ahead one hour on your bedside clock. Research shows that just one additional hour of...
More Answers
how does high blood pressure affect my health ?
Univ. of Nev. School of Medicine, Family MedicineUniv. of Nev. School of Medicine, Family Medicine
High blood pressure (hypertension) can affect your health by increasing your risk of heart attack, s...
More Answers
what are ways to control high blood pressure ?
Univ. of Nev. School of Medicine, Family MedicineUniv. of Nev. School of Medicine, Family Medicine
To control your blood pressure, you can do the following: Maintain a healthy weight and be physic...
More Answers
is early detection important ?
is early detection important ?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.