Understanding high blood pressure

For 85% to 95% of people with high blood pressure, the exact cause is unknown and there are usually multiple factors contributing; this is called essential hypertension or primary hypertension. For the other 5% to 10% of people, the cause can be linked to an underlying medical condition or medication. This is called secondary hypertension.

Reviewing medical and family histories often helps determine the underlying medical problem that led to high blood pressure. Some of causes of secondary high blood pressure include:

  • Cushing's disease
  • hyperthyroidism
  • hormonal disorders
  • kidney disease
  • medications such as hormonal contraceptives or corticosteroids

If you have secondary hypertension, the underlying cause will be managed first.

For essential hypertension, several factors increase the risk of high blood pressure. Some of the factors that you cannot control and that increase your risk are:

  • Age: The risk of developing hypertension increases with age. If you're over 55 years of age, you have a 90% chance of developing hypertension sometime in your life.
  • Ethnicity: People of South Asian, First Nations, or African heritage have greater rates of high blood pressure.
  • Family history: There is a higher chance of developing high blood pressure if your parents had the condition.

Other risk factors for high blood pressure are things that you can change and include:

  • Unhealthy eating: Eating a high-fat or high-salt diet can increase the risk of getting high blood pressure.
  • Alcohol intake: Drinking too much alcohol increases blood pressure.
  • Inactive lifestyle: Lack of physical activity decreases the rate at which the body burns calories. This type of lifestyle can lead to weight gain which is a risk factor for high blood pressure as well as other medical conditions such as diabetes.
  • Obesity: Excess fat, especially around the midsection, can increase your risk of developing high blood pressure. It is also a risk factor for developing type 2 diabetes and other conditions.
  • Smoking: This habit can lead to an increase in blood pressure in some people. Smoking is associated with atherosclerosis, which narrows the arteries and forces the heart to pump harder to move blood.

Talk to your doctor about your risk factors and what you can do to reduce your risk. To assess your risk, check out the heart disease risk calculator and other heart disease assessment tools. For more information on what you can do to reduce your risk, read about high blood pressure and lifestyle changes.