Sickle Cell Test
Blood sample from a vein
There is very little chance of a problem from having
a blood sample taken from a vein.
- You may get a small bruise at the site. You can
lower the chance of bruising by keeping pressure on the site for several
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (such as Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
Blood sample from a heel stick
Usually, there are no problems from a heel stick. A
small bruise may develop. Babies with bleeding problems may bleed more with
usual. Sometimes bleeding problems are found when blood is being collected for
the sickle cell test.
A sickle cell test is a blood test done
to screen for
sickle cell trait or
sickle cell disease.
Sickle cell test
hemoglobin is present.
Abnormal hemoglobin is
- In sickle cell trait, more than half of
the hemoglobin is normal (hemoglobin A) and less than half is abnormal
- In sickle cell disease, almost all hemoglobin is
hemoglobin S with some hemoglobin called
In babies, a sickle cell blood test may be repeated at 6
months old, or a genetic information (DNA) test may
What Affects the Test
Having a blood transfusion in
the past 4 months can cause a
false-negative test result because of the normal
hemoglobin from the blood donor.
What To Think About
- Most states routinely do a sickle cell blood
test on all newborns.
- If you have a family history of sickle cell
disease, you may be advised to have a blood test to determine whether you carry
the sickle cell trait. If you have sickle cell trait or sickle cell disease,
you may choose
genetic counseling before deciding to have
- Testing is available to check for sickle cell disease in
an unborn baby (fetus). This can be done through
chorionic villus sampling (CVS).
younger than 6 months of age may have false-negative results because they have more
hemoglobin F (fetal hemoglobin) in their blood.
- In the United
States, sickle cell disease mainly affects African Americans and Latin