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Sickle Cell Test

How It Is Done continued...

The health professional drawing blood will:

  • Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
  • Clean the needle site with alcohol.
  • Put the needle into the vein. More than one needle stick may be needed.
  • Attach a tube to the needle to fill it with blood.
  • Remove the band from your arm when enough blood is collected.
  • Put a gauze pad or cotton ball over the needle site as the needle is removed.
  • Put pressure to the site and then a bandage.

Blood sample from a heel stick

During newborn testing, the blood sample is usually taken from your baby's heel (called a heel stick).

  • Your baby's heel is cleaned with alcohol and then the heel is poked with a small needle.
  • Several drops of blood are collected inside circles on a special piece of paper.
  • When enough blood has been collected, a small bandage is put on the site.

How It Feels

The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.

Your baby may feel a sting or a pinch with a heel stick.

Risks

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 minutes.
  • 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.

Results

A sickle cell test is a blood test done to screen for sickle cell trait or sickle cell disease.

Sickle cell test2
Normal:

Normal hemoglobin is present.

Abnormal:

Abnormal hemoglobin is present.

  • In sickle cell trait, more than half of the hemoglobin is normal (hemoglobin A) and less than half is abnormal (hemoglobin S).
  • In sickle cell disease, almost all hemoglobin is hemoglobin S with some hemoglobin called hemoglobin F.

In babies, a sickle cell blood test may be repeated at 6 months old, or a genetic information (DNA) test may be done.

WebMD Medical Reference from Healthwise

Last Updated: October 01, 2012
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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