Low diastolic blood pressure is when blood pressure between heartbeats is lower than usual. Ways of managing it will be the same as for managing low blood pressure overall. Drinking more water and doing some exercise are two tips that may help.

Low diastolic blood pressure can cause symptoms such as dizziness and tiredness. Aging increases a person’s risk of low diastolic blood pressure.

This article will take a closer look at low diastolic blood pressure, including causes, symptoms, treatments, and more.

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Blood pressure readings use two numbers that doctors record in millimeters of mercury (mm Hg). The numbers measure systolic blood pressure and diastolic blood pressure.

Systolic blood pressure is the top number and is the higher of the two. It measures how much pressure the blood applies to the artery walls when the heart beats.

Diastolic blood pressure is the lower number, which shows the pressure the blood applies to the artery walls when the heart rests between beats.

A blood pressure reading will show the systolic blood pressure number first and diastolic blood pressure second. A doctor will assess a person’s blood pressure by considering both numbers.

In most adults, a healthy reading is usually less than 120/80 mm Hg. Low blood pressure, or hypotension, is blood pressure that is below 90/60 mm Hg.

Low diastolic blood pressure, or isolated diastolic blood pressure, is when the diastolic blood pressure falls below 60 mm Hg while the systolic blood pressure remains at a healthy level.

When the heart rests between beats, the coronary arteries receive and supply the heart with oxygen-rich blood. If the diastolic pressure is too low, the heart will not get the blood and oxygen it needs. This may cause the heart to weaken over time.

Learn more about understanding blood pressure readings.

What is a dangerously low diastolic blood pressure?

While there is no blood pressure reading that medical professionals consider to be too low, some studies suggest that diastolic blood pressure readings below a certain reading can increase a person’s risk of various conditions.

A 2016 study found that people with a diastolic blood pressure of either 60–69 mm Hg or below 60 mm Hg were at an increased risk of cardiovascular damage. A reading of below 60 mm Hg increased the risk of coronary heart disease over 21 years.

According to a 2018 study, diastolic blood pressure of below 70 mm Hg increases a person’s risk of heart attack and hospitalization due to heart failure.

It is best to contact a doctor for advice if a person has concerns about low diastolic blood pressure readings.

Learn more about when low blood pressure is an emergency.

A person who has low diastolic blood pressure may feel dizzy and tired. They may also fall more often. This can be particularly dangerous in older adults.

Usually, low blood pressure will not cause any issues. Within certain limits, it can be healthy to have low blood pressure.

Low blood pressure becomes a problem when other symptoms are present, such as:

Symptoms may subside when sitting down or resting. If blood pressure drops too low, the body’s vital organs will not get enough nutrients and oxygen to function correctly.

This could lead to the body going into shock. If this happens, a person should immediately seek medical attention.

Aging can increase the risk of low diastolic blood pressure. Older people who take medications for high blood pressure are also at higher risk of experiencing lower diastolic blood pressure.

Other medications can increase a person’s risk of low diastolic blood pressure, such as:

Some people naturally have lower blood pressure, which causes them no health problems. Other people may experience a drop in blood pressure due to an issue with their health. These issues can include:

Low blood pressure can also be due to:

Some people may also experience neurally mediated hypotension, where blood pressure drops after they have been standing for long periods.

Moving from lying down to standing up can lead to a dip in blood pressure. This is orthostatic hypotension, and may cause a drop in diastolic blood pressure by around 10 mm Hg. Symptoms of orthostatic hypotension may worsen in warm temperatures or after eating a large meal.

Treatment for low diastolic blood pressure is not always necessary. If doctors do recommend taking steps to increase blood pressure, there are numerous treatment options that can help, such as:

  • speaking with a doctor about changing certain medications
  • wearing compression stockings, which improve circulation
  • drinking water to increase blood volume and prevent dehydration
  • lifestyle changes a doctor recommends, such as changes in eating habits or methods of sitting and standing

Doctors may prescribe drugs to treat certain kinds of low blood pressure. However, there are currently no medications available to specifically treat low diastolic blood pressure.

Learn more about ways to inrease blood pressure.

To determine if a person has low diastolic blood pressure, a doctor will use a sphygmomanometer or blood pressure monitor. A doctor will consider a diastolic reading below 60 mm Hg to be low.

A doctor can carry out further tests to identify the cause of a person’s low blood pressure, including:

  • blood or urine tests
  • an electrocardiogram to read the heart’s electrical signals in order to detect the rhythm and any abnormalities
  • an echocardiogram to show detailed images of the heart

If the person finds that they faint often, the doctor may use a tilt table test. They use straps to secure the person to the table as it is tilted at different angles to see how the body reacts.

As age can be a cause of low diastolic blood pressure, it is not always possible for a person to prevent it. However, maintaining a moderate weight, eating a balanced diet, and getting enough physical activity or regular exercise can help keep blood pressure levels stable, as well as help keeping the heart healthy.

There are several lifestyle changes that someone with low diastolic blood pressure can make to manage their condition:

  • eating smaller meals
  • drinking more water
  • not sitting or standing still for long periods
  • getting up slowly when sitting or lying down

A person’s doctor can advise on more steps a person can take to manage their blood pressure.

In general, low blood pressure will not cause additional health issues. However, it can increase the risk of falls, which is particularly dangerous for older adults.

People with low diastolic blood pressure may also have an increased risk of heart attack and hospitalization from heart failure, so people must manage it as well as possible.

Symptoms of heart failure include:

Anyone experiencing symptoms of heart failure should seek immediate medical attention.

Diastolic blood pressure measures the pressure that the blood applies to artery walls between heartbeats. When diastolic blood pressure is low, the heart receives less oxygen-rich blood between beats.

Treatment is not always necessary for low diastolic blood pressure. However, a doctor may recommend lifestyle changes to help a person manage their blood pressure.

Low blood pressure is not always a cause for concerns. However, people with low diastolic blood pressure can visit their doctor regularly to help them monitor their blood pressure. The doctor can then quickly find any new issues that the low blood pressure is causing.