Causes Of High Diastolic Blood Pressure And What You Can Do To Lower It

Your blood pressure is a measure of the pressure of your blood pushing against your artery walls as your heart pumps it around your body. High blood pressure, also known as ‘hypertension,’ is a condition where blood flows through your arteries (blood vessels) at a pressure that is higher than usual. Normal blood pressure is less than 120/80mm Hg.¹

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About hypertension (high blood pressure)

Approximately 1.28 billion adults worldwide aged 30–79 have hypertension.² Hypertension is sometimes referred to as the ‘silent killer.’

Many people with hypertension have no symptoms or warning signs, so they aren’t even aware they have high blood pressure. Therefore, it's essential to have your blood pressure measured routinely, either at home with your own blood pressure cuff or at a doctor’s office.

Symptoms of high blood pressure

Typical symptoms of hypertension include:

  • Irregular heart rhythms

  • Morning headaches

  • Buzzing in ears

  • Nosebleeds

  • Vision changes

  • Dizziness

People with severe hypertension may experience:

  • Nausea

  • Vomiting

  • Fatigue

  • Chest pain

  • Anxiety

  • Confusion

  • Muscle tremors

How blood pressure is measured

Two numbers are used to measure blood pressure:

  • Systolic blood pressure: The top number on the blood pressure reading. It measures artery pressure when the heart beats.

  • Diastolic blood pressure: The bottom number of the blood pressure reading. It measures artery pressure when the heart rests between beats.

The measurement 120/80mm Hg refers to 120 systolic/80 diastolic and is measured in units of millimeters of mercury.

What causes diastolic blood pressure to be high?

Generally, both blood pressure numbers (systolic and diastolic) are elevated when it comes to hypertension. But, when your diastolic blood pressure is above 80mm Hg (considered high), and you have normal systolic blood pressure, it's called ‘isolated diastolic blood pressure.

Causes of isolated diastolic hypertension may include:

High-sodium diet

A diet that's high in salt disrupts your body's natural sodium balance, causing your body to retain water. This leads to increased pressure of the ‘pushing’ of your blood against your vessel walls.

One study found that, for people with hypertension, a 'no-added-salt diet' is the best approach. Following this diet for six weeks, both systolic and diastolic blood pressure decreased significantly.³

Obesity

According to a few large epidemiological studies, there's a link between blood pressure and body mass index in both overweight and normal-weight patients.⁴ Gaining weight in our adult years seems to be a particularly strong risk factor for developing hypertension. 

Not enough physical activity

The primary treatment and prevention of hypertension is exercise, an important element of lifestyle therapy. Various studies show the beneficial effects of physical activity on hypertension, with as large a reduction as 5–7mm Hg in systolic and diastolic blood pressure in people with hypertension.⁵

Excessive alcohol consumption

You can increase your blood pressure to dangerous levels by drinking too much alcohol. You temporarily raise your blood pressure by drinking more than three alcoholic beverages in one sitting.  When you binge drink, it can cause long-term blood pressure increases.

Some research shows that in individuals who drank more than two alcoholic beverages per day, decreased alcohol consumption was linked with reduced diastolic blood pressure.⁶

Anxiety and stress

Anxiety can elevate the systolic and diastolic blood pressure for some people. One 2016 study suggests mental stress could potentially activate a certain part of your nervous system, prompting a surge of hormones that disrupts how your body regulates blood pressure.⁷

More research is needed to understand the exact process of anxiety increasing blood pressure and why it occurs in only certain individuals, particularly in younger adults.

Certain medications can cause high diastolic blood pressure. These include:

  • Antidepressants

  • Amphetamines

  • Steroids

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)

  • Atypical antipsychotics

  • Caffeine

  • Oral contraceptive pills

  • Decongestants

Now we’ve examined some potential causes for elevated diastolic blood pressure, let’s briefly look at the causes of high systolic blood pressure.

What causes high systolic blood pressure?

When you have normal diastolic blood pressure, but your systolic blood pressure is high, it's called ‘isolated systolic hypertension.’ The American College of Cardiology states that isolated systolic hypertension can increase the risk of heart disease and even death in young adults.⁸

Certain medical disorders can cause you to develop isolated systolic hypertension. These disorders can frequently cause effects on the circulatory system, damaging blood vessels or contributing to the stiffening of arteries.

These disorders include:

Anemia

When your red blood cells don't function properly, or you don't have enough of them to deliver oxygen to your tissues, it can result in anemia. This can cause blood vessel damage as your heart works even harder to pump blood to your body's tissues to deliver enough oxygen.

Hyperthyroidism

Hyperthyroidism occurs when a person has an overactive thyroid, which is caused by an excess of thyroid hormones produced by your thyroid gland. This excess of thyroid hormone can affect virtually every internal organ, including your circulatory system and heart.

Diabetes

Diabetes occurs when you have high amounts of glucose in your blood. Over time, these high levels of glucose can cause numerous issues, including problems with your circulatory system and heart.

What does it mean if my diastolic blood pressure is high?

When your diastolic blood pressure is over 90mm Hg, it's often called ‘diastolic hypertension.’ The diastolic pressure of an adult should typically be 60–80mm Hg, and if the number goes above this, it's considered hypertension.

However, if your blood pressure goes over 180/120mm Hg, this is dangerous, and you should seek medical attention immediately.

High diastolic blood pressure has been associated with a few conditions, including:

Abdominal aortic aneurysm

High diastolic blood pressure has been associated with a higher risk of conditions that involve the aorta (the large artery) that carries oxygen and blood from your heart to your chest and abdomen.

For instance, individuals with an elevated diastolic blood pressure reading were more susceptible to developing an abdominal aortic aneurysm.⁹ This is an abnormal enlargement of your aorta and can result in rupture and risk of death.

Cognitive impairment

Several studies show that elevated diastolic blood pressure seems to be linked with memory deficits or cognitive impairment in individuals aged 45 or older. For every 10-point increase above 90mm Hg, it increases the risk of cognition issues by 7%.¹⁰

While there isn't an established causal relationship, treating or preventing high blood pressure may prevent cognitive impairment.

Stroke and brain issues

A diastolic blood pressure of 100mm Hg or above is linked with a substantial rate of strokes.¹ High blood pressure can lead to your arteries becoming blocked or bursting, causing a stroke.

During a stroke, brain cells die due to a lack of oxygen. A stroke can lead to severe disabilities in movement, speech, and other basic activities, and it can also kill you.

Chronic kidney disease

Adults with high blood pressure, diabetes, or both have a greater risk of chronic kidney disease than individuals without these conditions.¹

Symptoms of high diastolic blood pressure

High blood pressure may not cause significant symptoms.

It can take years for a person living with high blood pressure to notice any complications. You may experience symptoms such as blood spots in your eyes, headaches, dizziness, or other signs already mentioned in this article.

How can I lower my diastolic blood pressure immediately?

You can do several things to help lower your overall blood pressure, like taking prescription blood-pressure medication as directed by your doctor and making lifestyle changes such as minimizing salt and caffeine intake.

However, if you're only experiencing high diastolic blood pressure, you can’t address this alone. You'll have to work closely with your healthcare provider to decrease your diastolic blood pressure while ensuring it doesn't go below 60mm Hg.

When diastolic blood pressure gets too low, it can result in dizziness and fatigue. It may even cause heart damage and increase your risk of heart disease. According to a study, individuals with low diastolic blood pressure had a 49% chance of developing heart disease.¹¹

Here are some ways to lower your overall blood pressure, including diastolic blood pressure:

Reduce your intake of saturated and trans fats

Refrain from eating foods high in trans or saturated fats. Some examples include:

  • Hot dogs and other processed meats

  • Fast food

  • Frozen food

Try focusing instead on eating healthy polyunsaturated and monounsaturated fats in foods like olive oil, avocados, and nuts.

Eat heart-healthy foods

Foods that are an essential part of a diet that's healthy for your heart include:

  • Fish, especially those rich in omega-3 fatty acids

  • Vegetables, such as carrots, spinach, and broccoli

  • Skinless turkey or chicken

  • Fruit, such as bananas, oranges, and apples

  • Lean cuts of pork or beef

  • Nuts and beans

  • Eggs

  • Whole grains, such as whole-grain bread and brown rice

  • Low-fat or fat-free dairy products, such as yogurt and cheese

Exercise

Moderate physical activity, such as swimming, or brisk walking, can lower high blood pressure. You'll want to set goals that will help you safely exercise, and work your way up to a minimum of 2.5 hours (150 minutes) per week. Consult with your healthcare provider before beginning any exercise regime, particularly if you have any untreated health issues.

Avoid caffeine

Caffeine can increase blood pressure because it's a stimulant. You'll want to limit your caffeine intake if you have hypertension, especially before performing any activities that can further increase your blood pressure, such as exercising.

Decrease sodium in your diet

Limit your sodium (salt) intake to 1,500mg or less each day, since sodium can elevate blood pressure.

Consume more potassium

Potassium may counteract sodium's negative effect on your blood pressure. Therefore, increase your consumption of potassium-rich foods, such as spinach, bananas, and tomatoes. 

Maintain a healthy weight

Being obese or overweight can increase strain on your heart muscle, leading to an increase in blood pressure.

The American Heart Association (AHA) suggests that individuals maintain a body mass index (BMI) of between 18.5 and 24.9. When your BMI gets too high, you should take steps to lose weight.

The AHA also states that losing just 10lbs in weight is sufficient to lower blood pressure in overweight individuals. 

Consider taking prescription medicine

Your healthcare provider may prescribe medicine that helps lower your blood pressure. These types of medication include:

  • Calcium channel blockers

  • Thiazide diuretics

  • Angiotensin II receptor blockers

  • Angiotensin-converting enzyme (ACE) inhibitors

Take your blood pressure medication as directed

It's important to take your blood pressure medication as prescribed by your doctor. Don't cut back or stop taking it unless your doctor tells you to do so. If you have difficulty remembering to take your blood pressure medication, try setting reminders on your phone.

How do you treat high diastolic blood pressure?

Treatment aims to lower your blood pressure to decrease the risk of health issues caused by high blood pressure.

If you have a blood pressure reading between 120/80mm Hg and 130/80mm Hg, your doctor may suggest lifestyle changes to help bring your blood pressure down to the optimal range. At this stage, medication is rarely prescribed.

Stage I hypertension

If your blood pressure is lower than 140/90mm Hg but above 130/80mm Hg, your doctor may recommend lifestyle changes with one hypertensive medication.

Stage II hypertension

If your blood pressure is above 140/90mm Hg, your doctor may recommend you start taking rigorous medications and follow strict lifestyle changes. Typically, one medication is used at first. Your doctor may start you on another if you have consistently elevated blood pressure above 160/90mm Hg or stage II hypertension.

Beta-blockers

These medications slow down your heart rate and help relax the heart.

Diuretics (water pills)

These help your kidneys eliminate some salt (sodium) from your body, so your blood vessels don't have to retain as much fluid, as you can maintain blood pressure.

Angiotensin-converting enzyme (ACE) inhibitors

ACE inhibitors work on your kidneys, reducing your body's sodium retention. They also work on blood vessels directly, causing them to relax.

Angiotensin II receptor blockers

These work similarly to ACE inhibitors.

Alpha blockers

These help to reduce your blood pressure by a central action (the brain's blood pressure center) that helps relax the blood vessels.

Calcium channel blockers

These help to relax your blood vessels by decreasing the calcium that enters your cells.

Renin-inhibitors

This is a newer blood pressure treatment. These medications also help relax your blood vessels.

When should you see a doctor?

Early high blood pressure detection is essential. This ‘silent killer’ often shows no warning signs and therefore puts people at a higher risk of conditions such as:

Over 360,000 high-blood-pressure deaths occurred in 2016 in the US, whether hypertension was a contributing cause or the main cause.¹²

The only way to identify if you have high blood pressure is to measure it. You can visit your healthcare provider for regular blood pressure monitoring, or you can purchase a sphygmomanometer (blood pressure cuff) to measure your blood pressure at home.

If you're at risk of high blood pressure, you need to schedule routine healthcare visits to monitor your blood pressure. You should also see your healthcare provider if you have high blood pressure and your efforts to reduce your blood pressure have been ineffective.

The lowdown

Blood pressure control should be a lifelong task and part of your healthy living plan. The damage that high blood pressure can cause to your internal organs may not show any warning signs until there is already severe damage done; by then, it may be too late to reverse it.

By taking control of your health, you can help to keep your blood pressure under control. Some people can prevent high blood pressure, while others have uncontrollable factors, such as family history, which can increase their risk.

Exercising regularly, eating a well-balanced diet, and other healthy lifestyle changes may help lower systolic and diastolic blood pressure and prevent other health issues related to hypertension.

Always consult with your doctor if your blood pressure isn't improving in response to your attempts at healthy lifestyle changes.

Have you considered clinical trials for High blood pressure?

We make it easy for you to participate in a clinical trial for High blood pressure, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

Joining community groups and exercise programs for my condition made me feel empowered – but I want to be part of finding a cure.
Peter, 64

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