5 Main Causes and Risk Factors for High Blood Pressure

Hypertension (high blood pressure) is common, affecting over half of people in the United States over age 40. The most common type is primary hypertension, which has no identifiable cause but can stem from a variety of factors like unhealthy lifestyle habits (e.g., physical inactivity or a high-salt diet), genetics, and aging.

Secondary hypertension is less common, impacting around 10% of adults with high blood pressure. This type is directly caused by an underlying health condition, like kidney disease or sleep apnea, or taking medications, like certain painkillers or birth control pills.

1. Family History

Hypertension has a genetic basis, as the condition runs in families.

In developed countries like the United States, the risk of developing hypertension is up to 4 times higher if you have a family history of the disease compared to the general population.

The risk of hypertension increases if you have a parent or sibling with hypertension, as opposed to a second-degree relative (e.g., grandparent, aunt, uncle, or half-sibling).

Keep in mind that hypertension can occur without a family history. Likewise, having a family history of hypertension does not mean you will definitely develop it.

Experts believe that multiple genes, in combination with environmental/lifestyle influences, are what ultimately cause the disease to manifest.

2. Age and Race

Blood pressure increases with age, as arteries (blood vessels that carry oxygen-rich blood) naturally stiffen and harden with time.

The stiffening of arteries makes them more rigid and less elastic or flexible, impairing their ability to expand and stretch with blood flow.

Increasing Rates of Hypertension With Age

According to the Centers for Disease Control and Prevention (CDC), U.S. rates of hypertension are:1

• 22.4% of adults ages 18 to 39

• 54.5% of adults aged 40 to 59

• 74.5% of adults aged 60 and up

Regarding race, hypertension tends to be more common in Black individuals compared to White individuals. Hypertension in Black Americans also is usually more severe, manifests earlier in life, and is associated with more damage to vital organs, namely the kidneys, heart, and brain.

3. Lifestyle Factors

Several lifestyle habits or behaviors make a person more vulnerable to developing hypertension.

Risk factors include:

• Consuming an unhealthy diet, namely one that is high in sodium (salt) and low in potassium

• Daily consumption of alcohol

• Taking recreational drugs, such as cocaine and methamphetamine

• Not engaging in regular physical activity

• Not getting enough good-quality sleep

• Experiencing high-stress situations

4. Medical Conditions

Common health conditions that can cause hypertension include:

• Acute or chronic kidney disease is sudden or lifelong kidney damage, respectively. Kidney damage leads to excess fluid buildup within blood vessels, raising blood pressure.

• Primary hyperaldosteronism is the overproduction of aldosterone, a hormone made by the adrenal glands. High aldosterone levels cause high sodium and low potassium blood levels, leading to symptoms like high blood pressure, fluid retention, and weakness.

• Obstructive sleep apnea causes multiple breathing pauses during sleep, leading to excessive daytime sleepiness and an increased risk for hypertension.

Less common health conditions that cause hypertension include:

• Pheochromocytoma is a rare tumor in the adrenal gland.

• Cushing's syndrome stems from excess cortisol—the stress hormone—in the body.

• Congenital adrenal hyperplasia (CAH) is a rare genetic disease affecting the adrenal glands, causing an imbalance of hormones like aldosterone, cortisol, and androgen (male sex hormone).

• Hypothyroidism is an underactive thyroid gland, and hyperthyroidism is an overactive thyroid gland.

• Hyperparathyroidism is an overactive parathyroid gland.

• Aortic coarctation is a congenital (present at birth) narrowing of the aorta (the main artery carrying blood away from the heart)

5. Medications

Several medications can cause or contribute to hypertension. These include:

• Angiogenesis inhibitors (anticancer medicines that prevent the growth of new blood vessels), such as Avastin (bevacizumab)

• Antacids that contain sodium bicarbonate (baking soda), like Alka-Seltzer or Bromo-Seltzer

• Antidepressants, such as the tricyclic antidepressant Elavil (amitriptyline) or the selective norepinephrine reuptake inhibitor (SNRI) Effexor (venlafaxine)

• Atypical antipsychotics used to treat schizophrenia and bipolar disorder, such as Clozaril (clozapine) and Zyprexa (olanzapine)

• Birth control pills, especially those with higher doses of estrogen

• Cold medicines containing pseudoephedrine (e.g., Sudafed) or phenylephrine (e.g., Sudafed PE)

• Corticosteroids ("steroids") like prednisone

• Cyclosporine and tacrolimus (immunosuppressant drugs)

• Erythropoietin, used to treat anemia or low red blood cell count

• Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin or Motrin and Advil (ibuprofen)

• Stimulants used to treat attention deficit hyperactivity disorder (ADHD), such as Ritalin (methylphenidate)

• Tyrosine kinase inhibitors (targeted therapy, sometimes used to treat cancer), such as Sutent (sunitinib) and Nexavar (sorafenib)

Understanding Causes vs. Risk Factors

Most adults with hypertension have primary hypertension, meaning the condition exists on its own with no identifiable cause. Despite no known cause, individuals with primary hypertension often have one or more risk factors for hypertension.

Risk factors for hypertension are factors that increase a person's chances of developing high blood pressure. They can be fixed or non-modifiable, like a family history or advancing age, or modifiable, like a sedentary lifestyle or excessive alcohol or salt consumption.

Health conditions like diabetes or high cholesterol are also risk factors for hypertension.

Secondary hypertension is directly caused by an underlying health condition (e.g., kidney disease) or taking certain medications (e.g., chronic use of NSAIDs).

What’s the “Normal” Blood Pressure Range

According to the American College of Cardiology and the American Heart Association (ACC/AHA), normal blood pressure is less than 120/80 millimeters of mercury (mm Hg).

• The systolic pressure (the top/first number) measures the force placed against artery walls with each heartbeat.

• The diastolic pressure (the bottom/second number) measures the force placed against artery walls when the heart rests between beats.

Elevated blood pressure, sometimes called "prehypertension," is a systolic pressure between 120 and 129 mm Hg and a diastolic pressure less than 80 mm Hg.

Hypertension Stages

The ACC and AHA categorize hypertension as the following:

• Stage 1 hypertension: Systolic pressure between 130 and 139 mm Hg or diastolic pressure between 80 and 89 mm Hg.

• Stage 2 Hypertension: Systolic pressure at least 140 mm Hg or diastolic pressure at least 90 mm Hg.

What Causes Sudden High Blood Pressure?

Blood pressure naturally fluctuates throughout the day and can sometimes suddenly rise or "spike" due to certain causes, such as strong emotions or stress.

One common cause of a blood pressure spike is white-coat syndrome. It is defined as blood pressure that is consistently high when a person sees a healthcare provider but is within a normal range when taken outside of the provider's office.

The cause of white-coat hypertension is believed to be the triggering of a person's flight-or-fight response when in a medical setting, which leads to the release of hormones like adrenaline that raise blood pressure.

1. Other potential causes of sudden rises in blood pressure include:

2. Acute pain

3. Anxiety

4. Coffee or caffeinated energy drinks

5. Smoking and tobacco use

Hypertensive Emergency

A hypertensive emergency is when a sudden and extreme rise in blood pressure damages one or more vital organs, namely the eyes, brain, kidney, or heart.

This damage can lead to life-threatening complications, such as:

• Heart attack

• Heart failure

• Kidney failure

• Stroke

• Vision changes

When to Seek Emergency Care

Contact your healthcare provider if you have two or more blood pressure readings higher than 180/120 mm Hg.

Call 911 if your blood pressure is higher than 180/120 and you are having any of the following symptoms:

• Back pain

• Brownish or bloody urine

• Chest pain

• Confusion or trouble speaking

• Fainting or seizures

• Headache that's severe

• Nausea or vomiting

• Numbness or weakness on one side of the body

• Trouble breathing

• Vision changes (e.g., blurry or double)

How to Lower Your Blood Pressure

The ACC and AHA recommend treatment to achieve a blood pressure of less than 130/80 mm Hg. Treatment includes lifestyle interventions and, in many cases, medication.

Lifestyle Changes

The most essential lifestyle changes for managing hypertension are the following:

• Weight loss if overweight or having obesity: Strategies may include diet/exercise, bariatric surgery, or medications.

• Adopting the DASH diet (Dietary Approaches to Stop Hypertension diet): This diet involves a high intake of vegetables, fruit, low-fat dairy, whole grains, lean protein, and a low intake of red meat, full-fat dairy, and added sugars.

• Restricting salt intake: Foods high in salt include processed meats like bacon and cold cuts, frozen dinners, canned soup, and salted nuts.

• Increasing potassium intake: The World Health Organization (WHO) recommends consuming 3,510 milligrams daily (mg/day) of potassium to reduce blood pressure.

• Potassium-rich foods include apricots, lentils, raisins, oranges, and low-fat milk.

• Reducing alcohol consumption. A reduction in alcohol consumption lowers blood pressure in adults who drink more than two drinks per day.

• Increasing physical activity: The most significant reduction in blood pressure is apparent when individuals engage in aerobic exercise (such as brisk walking, running, or cycling) for 150 minutes weekly.

Speak With a Healthcare Provider

Talk with a healthcare provider before starting a new exercise regimen to ensure optimal health benefits and personal safety.

Medication

Starting an antihypertensive medication is an individualized decision, one that should be carefully discussed with your prescribing healthcare provider.

Treatment should be chosen from the following four categories of anti-hypertensive medications:

• Thiazide diuretics

• Calcium channel blockers

• Angiotensin converting enzyme (ACE) inhibitors

• Angiotensin-receptor blockers (ARBs)

Sometimes, therapy involves taking two medications, each from a different category.

Summary

Primary hypertension is the most common type of high blood pressure and has no known cause. Rather, it develops due to several factors, including modifiable ones like physical inactivity, high-salt diet, poor sleep quality, and chronic stress, as well as non-modifiable ones like a family history and increasing age.

Secondary hypertension is the less common type and develops as a direct result of an underlying health condition (e.g., kidney disease or sleep apnea) or medication (e.g., birth control pills, chronic use of NSAIDs, and certain antidepressants).

The American College of Cardiology (ACC) and American Heart Association (AHA) recommend a combination of lifestyle behaviors and medicine to achieve a blood pressure goal of less than 130 mmHg systolic and 80 mmHg diastolic.