Diagnosing a headache is like playing Twenty Questions. Experts
agree that a detailed question-and-answer session with a patient
can often produce enough information for a diagnosis. Many types of
headaches have clear-cut symptoms which fall into an easily
Patients may be asked: How often do you have headaches? Where is
the pain? How long do the headaches last? When did you first
develop headaches? The patient's sleep habits and family and work
situations may also be probed.
Most physicians will also obtain a full medical history from the
patient, inquiring about past head trauma or surgery and about the
use of medications. A blood test may be ordered to screen for
thyroid disease, anemia, or infections which might cause a
headache. X-rays may be taken to rule out the possibility of a
brain tumor or blood clot.
A test called an electroencephalogram (EEG) may be given to
measure brain activity. EEG's can indicate a malfunction in the
brain, but they cannot usually pinpoint a problem that might be
causing a headache. A physician may suggest that a patient with
unusual headaches undergo a computed tomographic (CT) scan and/or
magnetic resonance imaging (MRI). The CT scan produces images of
the brain that show structures or variations in the density of
different types of tissue. The scan enables the physician to
distinguish, for example, between a bleeding blood vessel in the
brain and a brain tumor, and is an important diagnostic tool in
cases of headache associated with brain lesions or other serious
disease. MRI uses magnetic fields and radio waves to produce an
image that provides information about the structure and
biochemistry of the brain.
An eye exam is usually performed to check for weakness in the
eye muscle or unequal pupil size. Both of these symptoms are
evidence of an aneurysm--an abnormal ballooning of a blood vessel.
A physician who suspects that a headache patient has an aneurysm
may also order an angiogram. In this test, a special fluid which
can be seen on an X-ray is injected into the patient and carried in
the bloodstream to the brain to reveal any abnormalities in the
blood vessels there.
Thermography, an experimental technique for diagnosing headache,
promises to become a useful clinical tool. In thermography, an
infrared camera converts skin temperature into a color picture or
thermogram with different degrees of heat appearing as different
colors. Skin temperature is affected primarily by blood flow.
Research scientists have found that thermograms of headache
patients show strikingly different heat patterns from those of
people who never or rarely get headaches.
A physician analyzes the results of all these diagnostic tests
along with a patient's medical history in order to arrive at a
Headaches are diagnosed as
- Muscle contraction (tension)
Vascular headaches--a group that includes the well-known
migraine--are so named because they are thought to involve abnormal
function of the brain's blood vessels or vascular system. Muscle
contraction headaches appear to involve the tightening or tensing
of facial and neck muscles. Traction and inflammatory headaches are
symptoms of other disorders, ranging from stroke to sinus
infection. Some people have more than one type of headache.