A lab test is a medical examination of blood, urine, saliva, or other body samples to diagnose diseases, monitor health conditions, and assess organ function. It helps detect infections, deficiencies, metabolic disorders, and various medical abnormalities. Common lab tests include blood tests, urine analysis, and microbiological cultures. These tests provide critical insights into a patient’s overall health and aid in early disease detection. Some lab tests require fasting or special preparations for accurate results. They are performed in hospitals, clinics, and diagnostic laboratories using advanced equipment. Lab tests play a vital role in preventive healthcare and treatment planning.