How It Is Done
Home or office sample
Three sputum samples are
usually collected over 3 days. Your doctor will give you a container to collect
the sputum. This container may have a small amount of liquid (called fixative)
in it. The fixative helps preserve the sample. Do not drink this liquid.
For best results, collect the sample in the morning right after waking
up. Follow these steps:
- If you wear dentures, remove them before
collecting the sample.
- Rinse your mouth with
- Take about four deep breaths followed by a few short coughs,
then inhale deeply and cough forcefully into the container. Sputum is not the
same as saliva, so make sure to get a sample of mucus from deep in your
Carefully follow your doctor's instructions about where
to deliver the sample. You may be instructed to take the sample to the doctor's
office or to a laboratory. Deliver the sample soon after you obtain it. You may
be instructed to refrigerate the sample if you are unable to deliver it
See the topic
Bronchoscopy for detailed information on how this procedure is done.
How It Feels
If you have discomfort when taking a deep
breath or coughing, getting a sputum sample may be uncomfortable.
For information on how a bronchoscopy procedure feels, see the medical
Home or office sample
There is no risk linked
with collecting a sputum sample at home or at your doctor's office.
Bronchoscopy is generally a
safe procedure. Although complications are rare, you should discuss the risks
in your particular case with your doctor. Complications that may occur
- Spasms of the bronchial tubes. These can
- Irregular heart rhythms
- Infection, such as pneumonia. These usually can be
treated with antibiotics.
Sputum cytology examines a sample of
sputum (mucus) under a microscope to determine whether abnormal cells are
present. It may take several days to receive results from a sputum
Normal lung cells are present in the sputum
| Abnormal: |
Abnormal cells are present in the sputum
Abnormal cells may indicate lung conditions such as
pneumonia, inflammation, the buildup of asbestos
fibers in the lungs (asbestosis), or
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include a sample that is
too small; is dried out; contains only saliva; or is from nasal secretions, not
What To Think About
- There is a chance of
false-negative test results with sputum cytology. This
means that the test shows a lung condition is not present when it actually
is present. Follow-up testing may need to be done if your symptoms
- Sputum is not the same as saliva. It is important to
obtain a sputum sample from deep in your airway. Collecting the sample in the
morning, when you first wake up, is generally best.
- If you have
trouble obtaining a good sample, try taking a hot shower first to help loosen
the mucus in your airway.
- A sputum culture is a test to find and
identify bacteria or fungi that are infecting the lungs or breathing passages.
It is also done to identify the best antibiotic to treat a lung infection. For
more information, see the topic
- Bronchoscopy or
a needle lung
biopsy are more commonly used than sputum cytology
because the results provide more information about airway problems. For more
information, see the topics