Cholesterol and Triglycerides Tests
How To Prepare
Preparation may depend on the type of test you are having. You may or may not have to fast.
- If your doctor tells you to fast before your test, do not eat or
drink anything except water for 9 to 12 hours before having your blood drawn.
Usually, you are allowed to take your medicines with water the morning of the
test. Fasting is not always necessary, but it may be recommended.
- Do not eat high-fat foods the night before the test.
- Do not drink alcohol or exercise strenuously before the
Many medicines may affect the results of this
test. Be sure to tell your doctor about all the nonprescription
and prescription medicines and herbs or natural substances you take.
Tell your doctor if you have had a test such as a thyroid or
bone scan that uses a radioactive substance within the last 7 days.
Talk to your doctor about any concerns you have regarding
the need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample
of your 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
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is
- Put a gauze pad or cotton ball over the needle site as the needle
- Put pressure on the site and then put on a bandage.
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 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
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 health
professional before your blood sample is taken.