Fainting

Fainting is a sudden, temporary loss of consciousness which usually results in a fall.

Medical professionals use the term ‘syncope’ when referring to fainting because the term helps to distinguish fainting from other causes of temporary unconsciousness, such as seizures (fits) or concussion.

Why does fainting occur?

In order to function properly, the brain relies on oxygen that is carried in the blood. Fainting occurs when there is an interruption to the brain’s blood supply.
 
In most cases, this is caused by a sudden malfunction to the autonomous nervous system, and is usually not serious. The autonomous nervous system is the part of the nervous system responsible for regulating many of the body’s automatic functions, such as heart beat and blood pressure.

A sudden fright can temporarily interrupt the workings of the autonomous nervous system, leading to a reduction of blood supply to the brain. Less commonly, and more serious, are interruptions to the blood supply that occur due to underlying problems with the heart.

How common is fainting?

Fainting is very common. It accounts for 3% of all visits to accident and emergency (A&E) departments, and 6% of all admissions to hospitals.

Although fainting can occur in people of all ages, it is most widespread in those who are 70 years old or over. It is estimated that 23% of people who are 70 or over will experience at least one episode of fainting.

Glossary

Pain

Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.

Brain

The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.

Blood vessels

Blood vessels are the tubes in which blood travels to and from parts of the body. The three main types of blood vessels are veins, arteries and capillaries.

Blood

Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.

Heart

The heart is a muscular organ that pumps blood around the body.

Oxygen

Oxygen is an odourless