What Is High Diastolic Blood Pressure?

Over one billion adults around the world have hypertension (high blood pressure), a condition that affects nearly half of the adult population in some areas. In the United States, high blood pressure is the leading cause of heart-related deaths and the second leading preventable cause of death overall, just after smoking.

High blood pressure is defined by elevated readings in either systolic (top number) or diastolic (bottom number) blood pressure measurements. A consistently high diastolic blood pressure can significantly increase your risk of heart-related conditions including heart attack, stroke, and dying from heart-related causes.

Systolic blood pressure tends to get more attention, but diastolic blood pressure is gaining recognition for its role in heart health. It's linked to conditions like heart failure, atrial fibrillation (irregular heartbeat), and kidney disease.

What Do Blood Pressure Readings Mean?

Blood pressure is measured using two numbers:

• Systolic blood pressure: The top number, which measures the force of blood against the walls of your arteries when your heart beats
• Diastolic blood pressure: The bottom number, which measures the force of blood against your artery walls when your heart is at rest between beats

According to the 2017 American College of Cardiology/American Heart Association guidelines, high diastolic blood pressure is defined as a diastolic blood pressure of at least 80 millimeters of mercury (mm Hg).

Blood pressure is categorized into different ranges to help identify potential health risks and guide treatment decisions. Blood pressure categories are defined as follows (measured in mm Hg):

A hypertensive crisis is a severe condition that requires immediate medical attention to prevent organ damage.

If a healthcare provider like a primary care provider (PCP) notices that your blood pressure is elevated over several visits, they might recommend lifestyle changes and possibly prescribe medications to help manage it. They'll also evaluate your risk for conditions like heart disease, heart attack, and stroke.

High Diastolic Blood Pressure Symptoms

High blood pressure typically doesn't come with noticeable warning signs or symptoms. It can quietly damage your body for years before symptoms develop—if they develop at all.

Taking your blood pressure regularly is the only reliable method to detect high blood pressure. This can be lifesaving. Early detection allows for timely intervention with lifestyle adjustments or medication to manage blood pressure.

Symptoms of very high blood pressure include:

• Headache
• Chest or back pain
• Shortness of breath
• Numbness or weakness
• Dizziness
• Vision changes (e.g., blurred vision)
• Arrhythmia (abnormal heart rhythm)

It's important to check your blood pressure regularly, even if you feel perfectly healthy.

What Causes High Diastolic Blood Pressure?

About 85% of high blood pressure cases don't have one known clear cause. This is known as primary hypertension.

Secondary hypertension has an identified cause, including conditions like:

• Obstructive sleep apnea (OSA): A chronic (long-term) sleep disorder that causes repeated breathing disruptions while you sleep
• Renovascular disease: A condition in which narrowed arteries affect blood flow into and out of your kidneys
• Primary aldosteronism: A condition in which your adrenal glands produce too much aldosterone, a hormone that helps regulate blood pressure

It's widely believed that eating too much salt can increase the risk of developing high blood pressure. This risk is partly related to genetics, particularly how your body responds to salt. Research shows that 50-60% of people with high blood pressure are sensitive to salt, which means they're more likely to develop high blood pressure if their salt intake is high.

Risk Factors

Many factors can contribute to high diastolic blood pressure. Genetics can play a role, so your risk might be higher if someone else in your family has high blood pressure. Age above 65 years old is another factor.

Other risk factors are more within your control. Modifiable risk factors include:

• A diet high in sodium and low in potassium
• Lack of physical activity
• Smoking
  
• Regular alcohol use (more than 1-2 drinks daily)
• Obesity

Systolic blood pressure generally increases with age, but diastolic blood pressure tends to decrease after around age 50. This is because arteries stiffen as you get older, making it more difficult for arteries to bounce back between beats.

How Is High Diastolic Blood Pressure Diagnosed?

High diastolic blood pressure is diagnosed using a blood pressure cuff during a medical examination. The process involves inflating a cuff around your upper arm and then slowly releasing the air while monitoring the pressure.

If you're diagnosed with high blood pressure, your healthcare provider may recommend a blood pressure machine to monitor your blood pressure at home​.They will also look for signs of conditions that can elevate blood pressure, such as:

• Narrowing of your aorta—the largest artery in your body, which carries blood from your heart to the rest of your body
• Heart valve disease
• Renovascular disease
• Kidney disease
• Thyroid disease

High Diastolic Blood Pressure Treatment

Lifestyle modifications are an important part of high diastolic blood pressure treatment. Medications might also be necessary.

Lifestyle Recommendations

Many lifestyle habits can help manage high blood pressure and reduce the risk of complications. Recommendations include:

• Limit sodium intake to less than 1,500 milligrams (mg) per day
• Focus on fruits, vegetables, and whole grains
  
• Limit alcohol
• Avoid smoking
• Manage stress
  
• Prioritize sleep (more than six hours each night)
• Engage in regular physical activity (The American Heart Association recommends 150 minutes of moderate aerobic activity weekly.)

Medications

Medications may also be prescribed to treat high diastolic blood pressure. Your healthcare provider will tailor them to your individual needs based on factors like age, ethnicity, and other health conditions. Possible blood pressure-lowering medications include:

• Angiotensin-converting enzyme inhibitors (ACEi)
• Angiotensin receptor blockers (ARBs)
• Diuretics
• Calcium channel blockers (CCBs)
• Beta blockers (BBs)

You might work with your healthcare provider to shift medications or dosage. Following your treatment plan is essential for managing high blood pressure.

Complications of High Diastolic Blood Pressure

If not managed, high blood pressure can cause complications like damaged arteries and blocked blood vessels. This can lead to conditions like:

• Heart attack
• Stroke
• Heart failure
• Kidney disease
• Vision changes
• Sexual dysfunction
• Chest pain (from heart disease)
• Peripheral artery disease (PAD)

High diastolic blood pressure for an extended period can also damage your blood vessels. This leads to a buildup of LDL cholesterol—"bad" cholesterol—along tears in the walls of your arteries.

How To Prevent High Blood Pressure

Adopting a healthy lifestyle can significantly lower your risk of high blood pressure. Prevention recommendations include:

• Eat a balanced diet rich in fresh fruits, vegetables, potassium, fiber, and protein, and low in sodium and saturated fat
• Engage in at least 150 minutes of moderate-intensity exercise weekly
• Avoid smoking
• Limit alcohol intake to 1-2 drinks per day
• Aim for at least six hours of quality sleep each night

The DASH diet plan is highly recommended for maintaining healthy blood pressure levels. It prioritizes vegetables, fruits, and whole grains and limits foods high in sugar, sodium, and saturated fats. 

A Quick Review

High diastolic blood pressure is when the lower number in your blood pressure reading is elevated. It indicates pressure in your arteries when your heart is at rest between beats.

High diastolic pressure can increase your risk of heart and blood vessel diseases, including heart attack and stroke. Managing high diastolic blood pressure often involves lifestyle changes, such as diet and exercise, and may require medication to lower your risk of related health complications.