How It Is Done
The health professional drawing blood
- 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
- Put the needle into the vein. More than one needle stick
may be needed.
- Attach a tube to the needle to fill it with
- Remove the band from your arm when enough blood is
- Put a gauze pad or cotton ball over the needle site as
the needle is removed.
- Put pressure to the site and then a
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
There is very little chance of a problem from
having 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 (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.
A hemoglobin electrophoresis test is a
blood test done to check the different types of
hemoglobin in the blood. Results are ready in several
The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
96.5%-98.5% of total
hemoglobin or 0.96-0.985 mass fraction
1.5%-3.5% of total
hemoglobin or 0.015-0.035 mass fraction
0%-1% of total
hemoglobin or 0-0.01 mass fraction
High and low values
- Higher-than-normal amounts of both hemoglobin
hemoglobin F may mean a mild form of
thalassemia is present. A very low level of hemoglobin
A and a high level of hemoglobin F may mean a more severe form of thalassemia.
High levels of hemoglobin F may be seen in a rare condition called hereditary
persistence of fetal hemoglobin.
- Hemoglobin S in moderate amounts
can mean that
sickle cell trait is present. Hemoglobin S in high
sickle cell disease.
- Hemoglobin C in low
amounts can mean that
hemoglobin C trait is present. Hemoglobin C in high
amounts means hemoglobin C disease, which causes anemia and an enlarged
- Hemoglobin types S and C mean hemoglobin S-C disease, which
causes a mild or moderate form of sickle cell disease.
- Hemoglobin E
in low amounts means the presence of
hemoglobin E trait. Hemoglobin E in high amounts means
hemoglobin E disease, which causes anemia and smaller-than-normal red blood
- Hemoglobin types other than S, C, D, and E are rare. But
over 400 types of abnormal hemoglobin have been found.