Evidence based

Low blood pressure – symptoms, causes, treatments and more

Jul 27, 2019 |
7 min read

Advertisement

When we think about high blood pressure and the problems it presents, it might seem like a good thing to have low blood pressure. In some instances, low blood pressure shows no issues.

However, if it is abnormally low, it can lead to problems such as fainting or dizziness. In some instances, it can prove life-threatening. (1)

If you have a blood pressure reading that is less than 90 millimeters of mercury (mm Hg) on the top number (systolic) and 60 mm Hg on the bottom number (diastolic), then your blood pressure is low.

Advertisement

There are several reasons why someone might suffer from low blood pressure. This can include dehydration or medical conditions. Therefore, you must identify the cause. This can then help you to find the right treatment.

See Also

High blood pressure - causes, symptoms, treatment and more

Low blood pressure – what are the symptoms?

In many cases, low blood can indicate an underlying medical problem. (2)

This is particularly true if it drops quickly. It can also present signs and specific symptoms, which include:

  • Dizziness
  • Light-headedness
  • Fainting
  • Nausea
  • Blurred vision
  • Fatigue
  • Loss of concentration

If you suffer from extremely low blood pressure, then it can pose a threat to life. (3)

It can lead to shock and the following symptoms or signs:

  • Confusion, which is common in the elderly
  • Pale skin that is cold and clammy
  • Shallow breathing that is also rapid
  • A rapid pulse that is also weak

If you experience these symptoms, then you should seek medical assistance. (4)

If you suffer from low blood pressure but present no symptoms, then your doctor will more than likely monitor you.

Even if you suffer from mild dizziness or light-headedness, then it could be a minor problem. It could relate to mild dehydration or too much sun exposure. However, any symptoms or signs should result in a visit to your doctor. (5)

This is because these symptoms could point to a severe problem. If you have regular symptoms, you should record them. You can then provide these to your doctor.

Causes of low blood pressure

Blood pressure relates to the amount of pressure within your arteries. This occurs during the resting and active phases of every heartbeat. (6)

When you have a blood pressure reading, the top number is the pressure that the heart creates when it pumps blood through the arteries and around the body. This is known as systolic pressure.

The bottom number of a blood pressure reading is called diastolic pressure. This relates to the pressure in the arteries as the heart rests in between beats. (7)

Blood pressure can alter throughout the day. It can depend on several things, such as the position of the body. The breathing rhythm also plays a part, as does your physical conditions.

Medications can also impact blood pressure along with the foods and drinks that you consume. At night, your blood pressure is generally at its lowest. (8) (9) (10)

Blood pressure – how low can it go?

We are all different. Therefore, what we class as low blood pressure in one person might not be for another.

As a result, low blood pressure becomes a problem when it presents symptoms. Some experts consider a reading of less than 90 mm HG systolic or 60 mm Hg diastolic as low blood pressure.

If your blood pressure drops quickly, then this can pose a threat. Even is change is as small as 20 mm Hg, then it can cause fainting and dizziness.

This is because the brain does not receive enough blood. Significant drops that are a result of bleeding or infection can prove a threat to life.

Conditions that cause low blood pressure

Many conditions lead to low blood pressure. This can include:

Pregnancy

During pregnancy, the circulatory system has to expand, and so, it can cause low blood pressure. This is considered normal, and once women have given birth, it will likely go back to where it was. (11)

Heart problems

There are heart conditions that might cause low blood pressure and this can including a low heart rate as well as heart attack, heart failure, and heart valve problems. (12)

Problematic endocrine

There are problems with the Thyroid, including parathyroid disease, low blood sugar, and adrenal insufficiency, and that can cause low blood pressure. (13)

Blood loss

If you lose a considerable amount of blood through injury or even internal bleeding, then this will reduce the amount of blood. Therefore, it can lead to a significant reduction in blood pressure.

Dehydration

If your body loses too much water, then it can lead to fatigue and dizziness.

Advertisement

If you are suffering from fever, vomiting, diarrhea, or you have undertaken too much exercise, then it can cause dehydration and low blood pressure.

Not enough nutrients

If you do not have enough nutrients, then this can lead to problems.  Not enough vitamin B-12, as well as folate, can prevent the body from creating red blood cells. This causes anemia and then a drop in blood pressure.

Severe infection

If you suffer from a severe infection such as septicemia, then a disease such as this can enter the bloodstream. This can cause septic shock, which can then cause a drop in blood pressure. This can then be life-threatening. (14)

Allergic reaction

If you suffer a severe allergic reaction, then it can lead to anaphylaxis. This can be life-threatening can be as a result of food allergies, insect venom, medications, and latex. This causes itching problems, swelling in the throat, and reduced blood pressure. (15)

The classes of low blood pressure

Low blood pressure will often be broken down into categories. This will depend on the causes as well as other factors. Therefore, low blood pressure types can include:

When standing up

When you get up from a seated position or lying down, it can cause a sudden drop in pressure. That is because gravity forces the blood to gather or pool in the legs.

To deal with this, the body will increase your heart rate. Therefore, blood vessels will constrict, helping the blood to reach the brain.

However, those who suffer from orthostatic hypertension cannot do this. Therefore, the body cannot compensate for the blood pooling. This causes dizziness, blurred vision as well as fainting. (16)

After meals

This can cause problems for older adults and is known as postprandial hypotension. After eating, blood flows to the digestive tract to aid digestion. Therefore, the body increases the heart rate. Along with this, it also constricts blood vessels to maintain blood pressure. However, this might not occur in all people, and this can lead to low blood pressure. (17)

Low blood pressure from damaged brain signals

This is known as neurally mediated hypotension. This problem occurs after people have been standing for significant periods. It commonly affects young adults and children. It is put down to, and the brain is not communicating correctly.

Low blood pressure from nervous system damage

This is known as multiple system atrophy with orthostatic hypotension. This is a rare disorder that is also known as Shy-Drager syndrome. This disorder causes slow damage to the autonomic nervous system. This controls many involuntary functions in the body, such as breathing, digestion, heart rate, and blood pressure. (18) (19)

Treatments for low blood pressure

Fortunately, it is possible to treat low blood pressure. This can be done via diet, lifestyle changes, and medication.

Increasing salt intake

While experts will say to limit your salt intake, adding small amounts of sodium to your diet can help. Therefore, your doctor might suggest that you increase your salt intake. However, it is important to get the balance right. Too much salt can lead to high blood pressure and heart failure. (20) (21)

Increase water intake

If you drink more water, it can increase the blood volume. This can prevent dehydration, which is a simple way of dealing with low blood pressure.

Compression stockings

These can help to prevent blood from pooling in the legs. This forces the blood to the upper body.

Medication

Some medications can be used. For low blood pressure that is associated with low blood pressure from standing up, then there is medication for this. There is also one to increase the blood pressure for those who suffer from severe orthostatic hypotension.

What are the risk factors?

Anyone can suffer from low blood pressure. However, certain factors can increase the risk.

Age

Adults over the age of 65 are at risk of low blood pressure. This can occur after they stand or eat.

Medication

Some medications can cause it. These can include high blood pressure medication as they can push the blood pressure too low.

Diseases

Diseases such as type 2 diabetes or Parkinson’s disease can increase the risk. (22) (23) (24)

Are there any complications?

People who suffer from low blood pressure can experience weakness, dizziness, and fainting. This can also increase the chance of injury from a fall.

If blood pressure drops severely low, then it can starve vital organs of oxygen. This can cause permanent damage to them.

Advertisement

More stories: