Laboratory tests Indications and Significance

Indications of Lab tests:
There are the following indications and significance for ordering any lab test are:
- To confirm the diagnosis of the disease.
- Some of these tests are confirmatory and some are suggestive of that disease. Confirmatory tests like Bone marrow examination for typing of leukemia.
- Hemoglobin to diagnose the anemia. Thyroid function tests for diagnosis of hypo or hyperthyroidism. Widal test to diagnose enteric fever.
- To help in the differential diagnosis:
- Lab tests help in the diagnosis of diseases like TLC in the case of acute appendicitis or other reason. LFT to find the type of jaundice.
- To know the prognosis:
- Lab tests help to know the progress of the disease like ESR in the case of Tuberculosis. Tumor markers in the treatment of cancers.
- To monitor the treatment:
- Lab tests help in the effectiveness of the treatment like chemotherapy in ovarian cancers or Renal function tests in renal disease. INR in anticoagulant therapy.
- As screening tests:
- Lab tests are done as panels for the diagnosis of disease in a community e.g. Screening in the blood bank of donors.