Low blood pressure is known as Hypotension.

It is possible for your blood pressure to become too low.  When this happens, it can lead to dizziness, fainting or even circulatory shock.

The effects of hypotension are usually transient.  In the majority of cases, when blood pressure is the cause of medical problems, it is because it is too high.  Generally, the advice is that lower is better. 

 

How low is too low?

The clinical definition is a blood pressure of 90/60 or lower.  For people suffering from low blood pressure, problems are usually immediate and short-lived, such as feeling faint on standing (postural hypotension) or throughout the day. 

 

What causes low blood pressure?

 

Hypotension is usually a result of low blood volume.  This can be due to sweating in hot weather, not eating or drinking regularly, pregnancy, haemorrhage, shock, and drug treatments that affect salt balance.  Particularly during exercise, blood volume becomes low due to loss of water and salt as sweat.  The pressure is maintained by the increase in heart rate.  This ensures that the brain and muscles can function adequately.  After exercise, when the heart rate returns to normal, the blood pressure will become low and will remain that way until volume is replaced by drinking and eating.  Blood pressure can also become excessively low during treatment for high blood pressure; in which case, the treatment should be adjusted accordingly. It is common in older people.

 

 

Postural hypotension

 

In some cases, blood pressure drops in response to changes in posture.  This is known as Postural Hypotension. 

Normally on moving from lying or sitting to an upright position, the blood is prevented from pooling in the lower body by constriction of the blood vessels.  This maintains the pressure in the upper body and head.  If this mechanism is impaired for any reason, or is too slow to react, the pressure in the head will become transiently low and may cause dizziness or fainting.  Some people experience these problems in fast moving elevators and similar situations.  This kind of hypotension is usually harmless unless fainting occurs often and becomes a problem.

 

What can I do about it?

 

The easiest and most effective way to raise low blood pressure is by drinking plenty of fluids to increase blood volume.  If symptoms arise at various times throughout the day, it may be useful to look closely at diet and eating habits.  Eating and drinking at regular intervals, especially when exercising regularly or under stress, will help to regulate blood pressure. 

If blood pressure is low because of drug treatment or other problems, such as dehydration or loss of blood, it may require medical intervention. 

When getting out of bed, sit on the side of it before standing for 30 seconds, and when standing from sitting, put your hand on a solid object to steady yourself.

   

02/06/2009