A screening test is done to detect potential health disorders or diseases in people who do not have any symptoms of disease. The goal is early detection and lifestyle changes or surveillance, to reduce the risk of disease, or to detect it early enough to treat it most effectively. Screening tests are not considered diagnostic, but are used to identify a subset of the population who should have additional testing to determine the presence or absence of disease.
What makes a screening test valuable is its ability to detect potential problems, while minimizing unclear, ambiguous, or confusing results. While screening tests are not 100% accurate in all cases, it is generally more valuable to have the screening tests at the appropriate times, as recommended by your healthcare provider, than to not have them at all. However, some screening tests, when used in people not at high risk for disease, or when testing for very rare diseases, can cause more problems than they help. Be sure to consult your healthcare provider regarding the appropriate timing and frequency of all screening tests based on your age, overall health, and medical history. The following are some examples of common screening tests: Cholesterol is a waxy substance that can be found in all parts of the body. It aids in the production of cell membranes, some hormones, and vitamin D. The cholesterol in the blood comes from 2 sources: the food you eat and production in your liver. However, the liver produces all of the cholesterol the body needs. Cholesterol and other fats are transported in the bloodstream in the form of spherical particles, called lipoproteins. The 2 most commonly known lipoproteins are low-density lipoproteins (LDL), or “bad” cholesterol, and high-density lipoproteins (HDL), or “good” cholesterol. Fecal occult blood is detected by microscopic analysis or by chemical tests for hemoglobin (blood) in the stool. People with blood in their stool may have a cancerous growth indicative of colorectal cancer. The test requires collection of 3 stool samples that are examined under the microscope for blood. This blood test measures the prostate specific antigen (PSA) levels in the blood. Antigens are any substances that evoke responses from a person’s immune system.
