Dizziness
(Dizzy)
Medical Author: Benjamin C. Wedro, MD, FACEP, FAAEM
Medical Editor: Melissa Conrad Stöppler, MD
Introduction to dizziness (feeling dizzy)
Dizziness is one of the most common symptoms that will
prompt an individual to visit a doctor. The term dizzy (or dizziness) can be
difficult to define because it can mean different things to different people. Does feeling dizzy refer to lightheadedness, the feeling of weakness and almost passing out, or does it
refer to vertigo (in
which the room or the person seems to spin)?
Dizziness (lightheadedness) is often caused by a decrease in blood supply to the brain,
while vertigo is caused by disturbances of the inner ear and the balance centers
of the brain.
It is necessary for patients and health care practitioners to work together
to understand the specific symptoms a patient is experiencing in order to make
the correct
diagnosis and treatment.
What are some common causes of dizziness?
While classifying dizziness into physiologic categories may help understand
how the body works, sometimes it is worthwhile to review common reasons why
people might complain of dizziness.
Low blood pressure
Dizziness, lightheadedness, and the feeling of passing out is a common
complaint in patients who have low blood pressure.
When the blood pressure is too low, not enough oxygen-rich blood
is being delivered to the brain, and its function can be affected.
In addition to feeling dizzy, associated
symptoms may include:
Low blood pressure can be the result of an underlying problem. Some common
reasons for low blood pressure include the following:
- Anemia (decreased red
blood cell count)
- Bleeding
- Dehydration (loss of
water in the body) often occurs with infections that cause
vomiting and
diarrhea.
Fever also can cause a significant amount of water loss due to increased
metabolic rate and excessive sweating
as the body tries to cool itself.
- Heat-related illnesses associated with dehydration such as
heat cramps,
heat exhaustion, or
heat stroke (a medical
emergency).
- Side effects of certain medications used to control blood pressure and heart rate.
Examples include:
- beta blockers
[propranolol (Inderal, Inderal
LA), atenolol (Tenormin),
metoprolol, (Lopressor, Toprol
XL)], which block adrenalin receptors
in the heart and may limit the heart rate from increasing in response to changes
in position.
- Nitroglycerin
and isosorbide mononitrate (Imdur Ismo, Monoket), a long acting nitroglycerin medication not
only dilate blood vessels in the heart, but may also cause other blood vessels
in the body to dilate and be unable to respond to the body's needs.
- Diuretics that can cause dehydration
- ACE inhibitors that slow the heart rate, and
- medications for
erectile dysfunction that can dilate blood vessels.
- Alcohol use
- Pregnancy
Next: Postural or orthostatic hypotension »
- diazepam, Valium - Describes the medication diazepam (Valium), a drug used for the short-term relief of symptoms related to anxiety disorders.
- Complete Blood Count (CBC) - A complete blood count (CBC) measures the concentration of white blood cells, red blood cells, and platelets in the blood and aids in the diagnosis of conditions and diseases such as anemia, malignancies, and immune disorders.
- Low Blood Pressure - Learn about low blood pressure (hypotension). Low blood pressure is blood pressure below normal and symptoms may include: lightheadedness, dizziness, fainting upon standing (orthostatic hypotension). There are many causes of low blood pressure, and treatment is dependant upon the cause.
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