How Is Sarcoidosis Diagnosed?
Your doctor will diagnose sarcoidosis based on your
medical history, a physical exam, and the results from tests. He or she will
look for granulomas (inflamed lumps) in your organs. Your doctor also will try
to rule out other causes of your symptoms.
Medical History
Your doctor may ask you detailed questions about
your medical history. For example, he or she may ask whether you have a family
history of sarcoidosis. Your doctor also may ask whether you've had any jobs
that may have raised your risk for the disease.
Your doctor also may ask whether you've ever been
exposed to inhaled beryllium metal. This type of metal is used to make
aircrafts and weapons. Your doctor also may want to know whether you've had
contact with organic dust from birds or hay.
Exposure to these substances can cause inflamed
lumps in your lungs that look like the granulomas from sarcoidosis. However,
these lumps are signs of other conditions.
Physical Exam
Your doctor will examine you for signs and symptoms
of sarcoidosis. Signs and symptoms may include red bumps on your skin; swollen
lymph nodes; an enlarged liver, spleen, or salivary glands; or redness in your
eyes. He or she will check for other causes of your symptoms.
Your doctor also may listen to your lungs and heart.
Abnormal breathing and heartbeat sounds may be a sign that sarcoidosis is
affecting your lungs or heart.
Diagnostic Tests
You may have tests to confirm a diagnosis and to
find out how the disease is affecting you. Tests include
chest
x ray,
lung
function tests, biopsy, and other tests to assess organ damage.
Chest X Ray
A chest x ray is a painless test that creates
pictures of the structures inside your chest, such as your heart and lungs. The
test may show granulomas or enlarged lymph nodes in your chest. About 95
percent of people who have sarcoidosis have an abnormal chest x ray.
Lung Function Tests
Lung function tests measure the size of your lungs,
how much air you can breathe in and out, how fast you can breathe air out, and
how well your lungs deliver oxygen to your blood. These tests may be used to
find out whether sarcoidosis is affecting your lungs.
Biopsy
Your doctor may do a biopsy to confirm a diagnosis
or rule out other causes of your symptoms. A biopsy involves taking a small
sample of tissue from one of your affected organs.
Usually, doctors try to biopsy the organs that are
easiest to access. Examples include the skin, tear glands, or the lymph nodes
that are just under the skin.
If this isn't possible, your doctor may use a
positron emission tomography (PET) scan to pinpoint areas for biopsy. For this
test, a small amount of a radioactive substance is injected into a vein,
usually in your arm.
The substance, which releases energy, travels
through the blood and collects in organs or tissues. Special cameras detect the
energy and convert it into three-dimensional pictures.
If lung function tests or a chest x ray shows signs
of sarcoidosis in your lungs, your doctor may do a bronchoscopy
(bron-KOS-ko-pee) to get a small sample of lung tissue.
During this procedure, a thin, flexible tube is
passed through your nose (or sometimes your mouth), down your throat, and into
the airways to reach your lung tissue. (For more information, see
"What
To Expect During Bronchoscopy.")
Other Tests To Assess Organ Damage
You also may have other tests to assess organ damage
and find out whether you need treatment. For example, your doctor may recommend
blood
tests and/or an
EKG
(electrocardiogram).
Everyone who is diagnosed with sarcoidosis should
see an ophthalmologist (eye specialist) for eye tests, even if they don't have
eye symptoms. This is important because eye damage can occur without
symptoms.
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