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Blood chemistry tests
Blood chemistry tests or panels are groups of tests that measure many chemical substances in the blood that are released from body tissues or are produced during the breakdown (metabolism) of certain substances. These tests are performed on a blood sample.
There are many different types of blood chemistry tests.
|Blood chemistry test||Substances measured|
kidney function tests
blood urea nitrogen (BUN)
liver function tests
alanine aminotransferase (ALT)
alkaline phosphatase (ALP)
aspartate transaminase (AST)
basic metabolic panel (BMP)
comprehensive metabolic panel (CMP)
Why a blood chemistry test is done
A blood chemistry test may be done to:
- evaluate a person’s general health status
- evaluate organ function
- evaluate the body’s electrolyte balance
- identify potential organ damage or injury
- identify damaged tissues that secrete chemicals into the blood
How a blood chemistry test is done
A blood chemistry test is usually done in a private laboratory or hospital laboratory. Preparation depends on the type of test being done.
- Fasting overnight may be required, especially if certain chemicals (such as glucose or lipid levels) are being tested.
- Blood is usually taken from a vein in the arm.
- A tourniquet or elastic band is wrapped around the upper arm to apply pressure to the area and make the vein swell.
- The person may be asked to open and close the fist to make the veins stand out more.
- The skin is cleaned and disinfected.
- A needle is inserted into the vein and a small amount of blood is removed.
- The person will feel a prick or stinging sensation.
- The sample is collected in a tube and labelled with the person’s name and other identifying information.
- The tourniquet is removed and the needle is withdrawn.
- Mild discomfort may be felt when the needle is withdrawn.
- Pressure is applied to the area where the needle was inserted until bleeding stops.
- A band aid may be applied.
- For some tests, the blood sample is allowed to clot and the clear yellow fluid (serum) that forms above the clot is carefully separated and removed for analysis.
- The sample is sent to a laboratory to be analyzed by special machines, examined under a microscope or both.
Potential side effects
Potential side effects of having a blood chemistry test include:
What the results mean
Normal ranges may vary from person to person and laboratory to laboratory. Many factors can affect blood chemistry results. Values may be abnormal for reasons other than cancer.
Increased blood chemistry values
|Component||An increased value may be due to||A decreased value may be due to|
ALT and AST
lactate dehydrogenase (LDH)
Note: Not all factors or conditions that can increase blood chemistry components are listed above. Only the main cancer-related ones have been included.
What happens if a change or abnormality is found
The doctor will decide if more tests, procedures, follow-up care or treatment are needed.