• Causes of High Blood Pressure (Hypertension)


    There are three types of high blood pressure (also known as hypertension):

    • Primary (also called essential) hypertension,
    • Secondary hypertension, and
    • Resistant hypertension.

    To determine which type you have, your doctor needs to find out whether a cause can be identified and whether standard treatments are able to control it.

    Primary or Essential Hypertension

    In most cases, the cause of hypertension is unknown. This is called primary or essential hypertension. Usually this type of hypertension increases slowly over many years. Although the causes can’t be identified, there are several risk factors that appear to raise your risk of developing hypertension. Some of the risk factors listed below are genetic, which mean you can’t change them. But the good news is many of the risk factors listed below are controllable risk factors, meaning you can change some of your lifestyle behaviors to lower your blood pressure.

    Uncontrollable Risk Factors

    • Age - The older you are, the higher your risk of hypertension.
    • Family history - Hypertension runs in families. Especially if your mother or father has hypertension, your risk for hypertension is increased.
    • Ethnicity - If you are from the Caribbean originally, or are black, you have an increased risk of hypertension.

    Controllable Risk Factors

    • Diet - Consuming a high-sodium, high-salt diet increases your hypertension risk. Following a low-sodium, heart-healthy diet full of vegetables and fruits lowers your risk of hypertension. Start by slashing sodium (salt) from your diet.
    • Exercise - Lack of exercise increases your risk of hypertension. Inactive people have higher heart rates, which makes your heart work harder and may increase blood pressure. More physical activity helps lower your risk.
    • Being overweight or obese - The more you weigh, the more blood your body has to pump around. This puts more strain on the blood vessels throughout your body, which increases your risk of hypertension. Losing weight helps control blood pressure.
    • Smoking - The nicotine in smoking products increases your risk of hypertension. Quitting smoking is one of the best things you can do to lower your hypertension and heart disease risk.
    • Drinking alcohol increases your risk. Avoid or limit alcohol to one drink (which is 1.5 ounces of liquor, or 5 ounces of wine, or 12 ounces of beer) per day for women or two drinks per day for men.

    Secondary Hypertension

    In some cases, an underlying cause of hypertension can be identified. This type of hypertension is called secondary hypertension and usually occurs as a more sudden increase in blood pressure. In this type of hypertension, if you can correct the problem that is causing the hypertension, your blood pressure will return to normal.

    For example, heart disease may be causing your kidney arteries to narrow with plaque (a process called renal artery stenosis). If this plaque can be removed through a procedure, such as an angioplasty and stenting, adequate blood flow can be restored through the arteries of the kidneys. This could help decrease your blood pressure back to normal levels.

    Another example is if you have obstructive sleep apnea.Treatment with a breathing machine called a Continuous Positive Airway Pressure (CPAP) machine at night would help your blood pressure to return to normal levels.

    A less common example of a condition causing secondary hypertension is an adrenal gland tumor. The adrenal glands sit on top of the kidneys and produce several hormones, including adrenaline (which is also known as epinephrine). These hormones are involved in the body’s normal stress response. In other words, the adrenal hormones help your body adjust its heart rate, blood vessel response and blood pressure during times of “fight or flight” stress. Sometimes a problem develops because a mass (tumor) causes too much of these hormones to be produced, resulting in high blood pressure. If an adrenal gland tumor is found, doctors may recommend surgery to remove the tumor. The surgery would also help blood pressure return to normal.

    Secondary hypertension can also be caused by a condition called primary aldosteronism, which makes the adrenal glands produce too much of the hormone aldosterone. This causes the body to retain too much sodium in the blood and to excrete too much potassium. Because of the increased sodium in the blood, the body holds in fluid, leading to high blood pressure. This condition can usually be treated with medication or surgery, which helps to return blood pressure to normal.

    Resistant Hypertension

    Sometimes hypertension is difficult to control even when several medications are prescribed. If three or more medications are needed and your blood pressure is still not under control, it is called resistant hypertension. About 30 percent of people with hypertension have resistant hypertension. People with resistant hypertension are at higher risk for stroke and heart attack. But a new treatment for resistant hypertension called renal denervation may be a possibility in the near future.

    Learn more about resistant hypertension and renal denervation here.