1) to diagnose diseases

2) to measure the progress or recovery from disease

3) to confirm that a person is free from disease

Some medical tests are parts of a simple physical examination which require only simple tools in the hands of a skilled practitioner, and can be performed in an office environment. Some other tests require elaborate equipment or the use of a sterile operating theatre environment.

Some tests require samples of tissue or body fluids to be sent off to a pathology lab for further analysis. Some simple chemical tests, such as urine pH, can be measured directly in the doctor's office.

Most medical tests are conducted on the living; however, some of these tests can also be carried out on a dead person as part of an autopsy.

Medical tests can be classified into three categories:

1) invasive

2) minimally invasive

3) non-invasive