Feeling faint?
By Dr Trisha Macnair
What is is?
Fainting is a temporary loss of consciousness, where the person
falls to the floor. It's sometimes called passing out.
Causes
A faint occurs when insufficient amounts of oxygen are reaching
the brain. There may be many reasons for this.
The most common is a vasovagal attack, where overstimulation
of a major nerve (the vagus) slows the heart rate and lowers blood
pressure. This overstimulation may be caused by intense stress,
fear, pain or anything that suddenly increases pressure inside the
body, such as blowing a trumpet.
Fainting may also result from low blood pressure,
or hypotension, often when someone stands up suddenly or is dehydrated
and low in body fluids. More rarely, fainting is due to abnormalities
of the heartbeat.
Who's affected?
Anyone may be affected by fainting, but people who are unwell or
dehydrated are at greater risk. Fainting - or feeling faint - is
also common in pregnancy.
Symptoms
The person may start to feel light-headed, dizzy, nauseous and sweaty.
They may have ringing in their ears and feel weak. Some people,
however, have little or no warning symptoms.
They then collapse to the ground and are unconscious
for a few moments before coming round. They may feel woozy or nauseous
for a little while afterwards and may vomit.
Diagnosis and treatment
After fainting, a person should return to normal fairly quickly.
If they don't, or have problems such as weakness or inability to
speak, it may be more than a simple faint.
The aim of treatment is to get more blood and
oxygen to the brain. Falling to the floor usually achieves this
because the head is then at the same level as the heart. Once on
the floor they should be put into the recovery position. If a person
is feeling faint but is not yet unconscious, they should lean forwards
with their head between their knees or, ideally, lie down with their
feet raised above the level of their head.
Further help
In most cases the person soon feels better, especially if given
a drink and allowed to rest. If they don't regain consciousness
within a minute or two, or if they have symptoms afterwards, urgent
medical help should be sought. Repeated episodes of fainting should
also be investigated further.
-BBC Health |