|
Dear Mayo
Clinic: I had a fainting spell the other day, which had never
happened to me before in my 64 years. I don’t feel unwell,
but a friend I was with at the time insists I should see my
doctor. Is that necessary? What would they be looking for?
A: Yes, make an
appointment to see your health care provider. Fainting, or
passing out — a temporary loss of consciousness also known
as syncope — is caused by insufficient blood flow to the
brain. Some causes of syncope are fairly benign, such as from
dehydration, or during a frightening or uncomfortable event,
such as a blood draw. But there are potentially serious and
even life-threatening causes, including heart and neurological
conditions, especially in adults over 60.
Your health
care provider likely will perform a detailed history to look
for any medical, environmental or behavioral factors that may
have caused you to faint. For example, missed doses of a
medication, prolonged standing or anxiety in a crowd may
contribute to syncope.
A physical
examination may offer important clues, as well. This includes
measurement of your blood pressure and heart rate, listening
to your heart, and completing a neurological exam.
Syncope occurs
when your blood pressure falls too low, which may occur when
your heart rate is excessively fast or slow, such as with an
arrhythmia. Examples of heart disturbances that could cause
syncope include bradycardia, a slower-than-normal heart rate;
tachycardia, a faster-than-normal heart rate while at rest;
and aortic stenosis, a narrowing of the heart’s aortic
valves. Neurological conditions such as a seizure or a
transient ischemic attack, often called a “ministroke,”
also can result in loss of consciousness.
A condition
known as vasovagal syncope, sometimes called
“neurocardiogenic syncope,” occurs when you faint as a
result of your body overreacting to certain triggers, such as
the sight of blood or extreme emotional distress. The trigger
causes the part of your nervous system that regulates heart
rate and blood pressure to drop suddenly, reducing blood flow
to the brain and causing you to faint.
A detailed
history and exam may identify the cause of syncope. Often, an
EKG or additional heart testing also will be recommended to
look for any abnormal heart rhythms. Other tests may include a
complete blood count, electrolyte panel, and tests of your
blood sugar and thyroid function. You may be referred for a
heart ultrasound (echocardiogram), stress test or tilt table
test. If you took a hard fall, imaging tests may be performed
to look for fractures or other trauma.
Management of
syncope depends on the underlying cause. Most often it
involves learning to avoid triggers and recognize warning
signs. Pay attention if you begin to feel lightheaded, dizzy
or clammy, or if you have unusual sweating, nausea or heart
palpitations. Sit or lie down until you feel stable or are
able to call for assistance. Be sure to be evaluated if this
occurs.
The fainting
spell you experienced may be a one-time occurrence, but it’s
still in your best interest to see your health care provider
so he or she can determine what, if anything, should be done
to explore the cause further.
|
