WWhhyy l llaabboor rraat ttoor rryy t tteesst ttss aar rree oor rrddeer rreedd??<br />To screen for disease (screening tests as ESR , CBC)<br />To confirm a diagnosis<br />To exclude a disease that is possible but not likely<br />To aid differential diagnosis, e.g. to distinguish between different forms of jaundice.<br />To assess the severity of disease, e.g. plasma [urea] or [creatinine] in renal disease.<br />To determine risk factors for disease as lipid profile<br />To monitor progress of disease, e.g. plasma glucose to follow of patients with diabetes.<br />To monitor effectiveness of disease treatment as in case of anticoagulant therapy.<br />To detect complications or side-effects of drugs e.g. aminotransferase measurements in<br />patients being treated with hepatotoxic drugs.