What can happen if you have low blood pressure

When the heart is squeezing blood into the arteries, the pressure is high. When the heart is relaxed, the pressure is lower.

Your blood pressure is a measurement taken of the highest reading and the lowest reading. It is given as 2 figures — highest over lowest. Blood pressure is measured in ‘mmHg’, which refers to millimetres of mercury.

What is low blood pressure?

Low blood pressure is also known as hypotension.

Most doctors would say that you have low blood pressure if it is below 90/60 mmHg. Your doctor will refer to this as ‘90 over 60’.

Is low blood pressure a problem?

For some people, low blood pressure is a sign of good health. These are generally people who are very fit and who have a slow pulse. For other people, low blood pressure is a problem.

Often, people with low blood pressure can be expected to lead longer lives.

However, people who experience continuing symptoms of low blood pressure should see a doctor. Sudden, severe low blood pressure (shock) can be associated with serious medical conditions.

What are the signs and symptoms of low blood pressure?

The symptoms of low blood pressure may include:

These symptoms can occur when doing nothing. They are more likely to occur when changing position, such as standing up or when straining on the toilet.

However, often there are no symptoms and low blood pressure is often only identified as a result of a routine medical examination or during the course of an investigation for some other condition or underling illness.

Low blood pressure may be more serious in elderly people who may have an underlying illness or who may be at risk of a fall.

Check your symptoms with healthdirect’s Symptom Checker to get advice on when to seek medical attention.

What causes low blood pressure?

Apart from being very fit, people can have low blood pressure if they:

• are overheated, either from the weather, from hot baths or showers, or from wearing too many clothes
• have too little blood circulating, either from donating blood, from bleeding heavily, or from being dehydrated
• are pregnant
• are taking one of many different types of medicines
• have a lot of drugs or alcohol in the system

People can also have low blood pressure due to medical conditions, such as if they:

There is also a particular type of low blood pressure called ‘postural hypotension’ or ‘orthostatic hypotension’. In this condition, a person’s blood pressure is normal when they are sitting or lying down, but it drops suddenly when they stand, making them feel dizzy or lightheaded. This can also occur when standing too long without moving.

Postural hypotension is fairly common, particularly in older people. It can be caused by one of the situations or conditions listed above. If it happens often, or if it causes problems, you should see your doctor about it.

When should I see a doctor?

If you think you might have symptoms of low blood pressure listed above, it’s best to see your doctor.

How is low blood pressure treated?

If there is an underlying cause for your low blood pressure, and it is giving you problems, you may need treatment for that underlying cause. But if it isn’t causing you problems, treatment won’t be needed.

Your doctor may advise you to take precautions to prevent episodes of low blood pressure, such as avoiding dehydration, hot showers or standing up too quickly.

Also called hypotension, low blood pressure is not a problem if you’re healthy and show no signs or symptoms of the condition. However, abnormally low blood pressure can cause problems such as dizziness and fainting and can be a sign that other serious conditions, such as heart disease, are present.

What Is Blood Pressure?

Blood pressure is measured in millimeters of mercury (mmHg). Systolic pressure is listed first (or the “top” number), then diastolic pressure (or the “bottom” number).

Normal blood pressure in adults is less than 120/80 mmHg. Low blood pressure is a reading below 90/60 mmHg.

Most forms of hypotension happen because your body can't bring blood pressure back to normal or can't do it fast enough.

For some people, low blood pressure is normal. They have it all the time, with no symptoms or negative side effects.

In other people, abnormally low blood pressure is caused by certain medical conditions or factors. When this happens, less blood and oxygen flow to the body's organs.

Symptoms And Causes Of Low Blood Pressure

Many different conditions and situations can cause low blood pressure, from standing up too fast to being pregnant. Sometimes, low blood pressure is linked to an underlying problem. That’s why it’s important to see your doctor right away if you experience the signs of low blood pressure.

Symptoms of low blood pressure can include:

• Dizziness
• Fainting
• Dehydration
• Lack of concentration
• Blurred vision
• Nausea
• Cold, clammy and pale skin
• Rapid, shallow breathing
• Fatigue
• Depression

Low blood pressure can be a sign of serious heart, endocrine or neurological conditions. If left untreated, the brain and other vital organs do not get the oxygen and nutrients they need. In extreme cases, this can cause shock, a life-threatening condition.

If you show signs of low blood pressure, your doctor will conduct an exam and may perform tests to determine what’s causing the condition. Low blood pressure can occur with many other conditions.

Some causes of low blood pressure are:

• Prolonged bed rest, in which circulation decreases due to lack of movement
• Heart problems that prevent the heart from being able to circulate enough blood
• Endocrine problems, such as an under-active thyroid
• Pregnancy. Blood pressure often drops in the first 24 weeks of pregnancy.
• Decrease in blood volume from trauma, dehydration, or internal bleeding
• Certain medicines. Medicines that treat hypertension, heart conditions, Parkinson’s disease, depression, and erectile dysfunction can lower blood pressure.
• Nutritional deficiencies, such as a lack of vitamin B-12 and folic acid, may lead to anemia, which can cause low blood pressure.
• Severe infections like septic shock, when bacteria enter the blood stream
• Severe allergic reaction (anaphylaxis) that causes problems with breathing and sudden drop in blood pressure
• Postural (orthostatic) hypotension, a rapid blood pressure drop when standing from a sitting or lying down position
• Neurally mediated hypotension, which is a blood pressure drop after standing for long periods

Living With Low Blood Pressure

Medicines and lifestyle changes can help you live safely with chronic low blood pressure. Your doctor can recommend steps you can take to manage your low blood pressure. These actions can help control the condition:

Drink more water. This can help avoid dehydration.

Medicines and lifestyle changes can help you live safely with chronic low blood pressure.

Avoid alcohol. Alcoholic beverages are dehydrating, and alcohol changes how medicines work in your body.

Slow down. Take your time when standing up. If lying down, sit up first. Then wiggle your feet and move your legs. This will increase circulation and get your heart rate up so that you don’t feel lightheaded when you stand up.

If your medicine and lifestyle changes do not reduce your low blood pressure symptoms, talk with your doctor about other changes you can make.

Are there dangers to low blood pressure?

What do you do if your blood pressure is too low?

When is low blood pressure an emergency?

What can cause low blood pressure?