Transient ischaemic attack (TIA)

Causes of a transient ischaemic attack

Transient ischaemic attacks (TIAs) occur when one of theblood vessels that supply your brain with oxygen-rich blood becomes blocked.

This interruption in the flow of bloodto the brain means that the braincannot carry outsome of its normal functions properly, leading to symptoms such as slurred speech and weakness.

In TIAs, the blockage quicklyresolves and your brain's blood supply returns to normal before there's any significant damage. In a full Heat exhaustion and heatstroke , the blood flow to your brain is disrupted for much longer, leading to more severe damage to the brain andlonger-term problems.

The blockage inthe blood vessels responsible for most TIAs is usually caused by a blood clot that has formed elsewhere in your body and travelled to the blood vessels supplying the brain, although it can also be caused by pieces of fattymaterial or air bubbles.

In very rare cases,TIAs can be caused by a small amount of bleeding in the brain known as a haemorrhage.

Blood clots

Blood clots that cause TIAs typically form in areas wherearteries have been narrowed or blocked over time by the build-up of fatty deposits known as plaques. These plaques are formed during a process called atherosclerosis .

As you get older, the arteries can become narrower naturally, but certain things can dangerously accelerate the process. These include:

smoking
high blood pressure (hypertension)
obesity
high cholesterol levels
diabetes
excessive alcohol consumption

Atype of irregular heartbeat called atrial fibrillation can also cause TIAs. It can lead to the formation of blood clots that escape from the heart and become lodged in the blood vessels supplying the brain.

Who's most at risk?

Certain things can increase your chances of having a TIA. Some of these factors are changeable such as your lifestyle.

Some of themainrisk factorsfor TIA are:

age although TIAs canoccur at any age (including in children and young adults), they aremost common in people over 60
ethnicity people of south Asian, African or Caribbean descent have a higher TIA risk, partly because rates of high blood pressure are higher in these groups
medical history as well as the conditions mentioned above, other health conditions such as diabetes can increase your risk of having a TIA
weight and diet your risk of having a TIA is higher if you are overweight and/or have an unhealthy diet high in fat and salt
smoking and alcohol smoking and/or regularly drinking excessive amounts of alcohol can increase your TIA risk