Low blood pressure is given the medical term “Hypotension” (as opposed to hypertension which is high blood pressure). Low blood pressure occurs when the pressure in the blood vessels falls below normal limits. Although different sources have different criteria for low blood pressure, we can assume that anything below 90/60 is low.

It is very difficult to define exactly what constitutes low blood pressure, since everyone is different. One person may suffer symptoms at 90/60 while another is totally fine at blood pressures which theoretically should have them on their back.

If you have no symptoms there is no reason for concern. Only when blood pressure drops below the level required by your body and cells, is there a real problem. When this happens, you get symptoms.

Symptoms of low blood pressure

• Dizziness
• Lightheadedness
• Fainting

Under severe low pressure, symptoms can include chest pains. Also, without the necessary pressure in the blood, the kidneys cannot filter out the toxins in your blood, and there will be an increase in blood levels of urea and creatine.

Causes of Low Blood Pressure

Low blood pressure can have a variety of causes including:

• Medication, including high blood pressure medicine, and medication for coronary heart disease.
• Anti-anxiety, and anti-depressant drugs.
• Diuretics
• Alcohol
• Dehydration – common when someone has diarrhea and-or vomiting. It is important to drink plenty of fluids (plain water works best) if you are ill with these.
• Slow heart beat
• Inflammation of organs in the body, e.g. acute pancreatitis
• Heart disease – when the walls of the heart become weakened and can no longer pump with the required force.

Should you consult a doctor?

Yes if:

• You lose consciousness when you stand up
• You constantly feel weak, light headed or tired.

Facts on low blood pressure

In younger people, low blood pressure can be a sign of chronic fatigue syndrome.

In older people, low blood pressure can indicate heart disease.

Young women (below 40) may find their blood pressure drops below 90/60 during:

• pregnancy
• hot weather
• dieting

Treatment for Low Blood Pressure

Since any treatment will depend on the cause of your low blood pressure, you must consult your doctor. It may be that some component of your lifestyle has caused the low blood pressure, and simple changes to that can restore your blood pressure to normal.

The pressure of your blood depends on a number of factors including:

• the force created by your heart pumping blood into your arteries
• the volume of your blood
• the resistance your blood encounters as it moves through your blood vessels.

You body needs to make sure that there is sufficient pressure to push the blood into all of the capillaries around your body. Capillaries are the smallest blood vessels in your body, and ensure that all cells in your body receive nutrients they require to live.

Maintaining normal blood pressure is delicately balanced. Too high, and your heart and blood vessels are put under strain. Too low and the low blood pressure means some cells may not get the nutrients they require.

High blood pressure is often called the “Silent Killer” since there are often no symptoms. For this reason, it is important you get your blood pressure checked regularly.

Blood pressure readings can be taken by your doctor using a sphygmomanometer and stethoscope, or at home using a blood pressure monitor (the easiest ones to use are digital monitors). The home monitors generally come in two forms. One places a cuff around your wrist, while the other places a cuff around your upper arm (level with your heart). I personally have tried both types and found the most accurate one to be the upper arm cuff.

The blood pressure “numbers”

The blood pressure reading is two numbers. These are the two pressures of your blood at varying stages of your heart beat cycle:

The larger number is the systolic pressure, the lower number is the diastolic pressure.

Systolic pressure is the blood pressure being pumped into the aorta when the heart beats.

Diastolic pressure is the blood pressure in the arteries when the heart relaxes between beats.

Blood pressure does vary with age, sex and health, but in general, a healthy blood pressure is 120/80, or 120 over 80.

This means that systolic blood pressure is 120 mmHg, and the diastolic blood pressure is 80 mmHg.

Your blood pressure can actually tell a doctor a lot about the health of your heart and blood vessels. High blood pressure means that your heart is having to work harder to push your blood to all the cells in your body.

This can happen if e.g. you have narrowing of the arteries, since this narrowing increases the resistance of your blood vessels, and requires more pressure to get the blood through.

High blood pressure is also called hypertension, and can have serious consequences if not treated. e.g. high blood pressure can weaken the artery walls, and lead to rupture. If this happens in the brain, it can lead to a stroke.

There are a wide range of medicines and medications available to treat high blood pressure, and some alternative therapies such as acupuncture may also help, but you can also take immediate steps by looking at your diet and increasing your daily exercise (walking is a great exercise).

We explore some of the dietary considerations on this site, but please do consult a doctor before changing your diet or undertaking an exercise program.