What Is a Blood Test?
A blood test is when a sample of blood
is taken from the body to be tested in a lab. Doctors order blood tests to check things
such as the levels of glucose, hemoglobin, or white blood cells. This can help them
detect problems like a disease or medical condition. Sometimes, blood tests can help
them see how well an organ (such as the liver or kidneys) is working.
What Is a Lead Test?
A lead test measures how much lead
is in the blood. Lead is a metal that is found in the environment and in many consumer
products. Most people have a small amount of lead in their blood from these exposures.
But higher levels of lead can lead to problems in children, such as learning disabilities,
behavior problems, and anemia. Very
high levels can cause serious problems, such as seizures
or a coma.
Why Are Lead Tests Done?
A lead test may be done if a child is at risk for a high lead level. For example,
kids who live in older homes or in communities with many older homes are at risk for
high lead levels.
How Should We Prepare for a Lead Test?
Your child should be able to eat and drink normally unless also getting other tests
that require fasting beforehand. Tell your doctor about any medicines your child takes
because some drugs might affect the test results.
Wearing a T-shirt or short-sleeved shirt for the test can make things easier for
your child, and you also can bring along a toy or book as a distraction.
How Is a Lead Test Done?
Most blood tests take a small amount of blood from a vein. To do that, a health
professional will:
- clean the skin
- put an elastic band (tourniquet) above the area to get the veins to swell with
blood
- insert a needle into a vein (usually in the arm inside of the elbow or on the
back of the hand)
- pull the blood sample into a vial or syringe
- take off the elastic band and remove the needle from the vein
Lead is sometimes tested with a "fingerstick" test. The health professional will
clean your child's finger, then prick the tip of it with a tiny needle (or lancet)
to collect the blood.
In babies, blood draws are sometimes done as a "heel stick collection." After cleaning
the area, the health professional will prick your baby's heel with a tiny needle (or
lancet) to collect a small sample of blood.
Collecting a sample of blood is only temporarily uncomfortable and can feel like
a quick pinprick.
