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Toxicology Tests

How It Feels

Blood test

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.

Urine test

There is no pain while collecting a urine sample. A trained person of the same sex may need to watch you during the urine collection. This may make you feel uncomfortable.

Saliva test

There is no pain while collecting a saliva sample. A trained person will be present to either collect the sample or watch you collect the sample.

Risks

Blood test

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 (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.

Urine test

There is no chance for problems while collecting a urine sample.

Saliva test

There is no chance for problems while collecting a saliva sample.

Results

A toxicology test examines blood, urine, or saliva for the presence of drugs. Most toxicology tests determine only the presence of drugs (called qualitative testing) in the body and not the specific level or quantity. Follow-up testing is often required to determine the exact level of a certain drug in the body (called quantitative testing) and to confirm the results of initial testing.

Toxicology tests
Normal:

No unexpected drugs are found in the blood, urine, or saliva.

Levels of prescription or nonprescription medicines found in the blood, urine, or saliva are within the effective (therapeutic) range.

Abnormal:

Unexpected drugs are found in the blood, urine, or saliva.

Levels of prescription or nonprescription medicines found in the blood, urine, or saliva are too low or too high to be effective (therapeutic) or potentially toxic, if too high.

High values

High levels of prescription or nonprescription medicines may be caused by a drug overdose, either accidental or intentional. A drug overdose may be caused by one large dose of medicine or long-term overuse of a medicine. Interactions between medicines also can cause problems, especially if you start taking a new medicine. A high level may mean that a person is not taking his or her medicine correctly or that the medicine is not being properly processed by the body.

Low values

Low levels of prescription or nonprescription medicines may mean that a person is not taking his or her medicine correctly.

WebMD Medical Reference from Healthwise

Last Updated: November 07, 2011
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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