A blood specimen is a sample of blood taken from a person for medical testing. This sample can be collected through a simple procedure, often using a needle to draw blood from a vein in the arm. Blood specimens are essential for diagnosing various health conditions, monitoring diseases, and assessing overall health. Once collected, the blood specimen is usually placed in a sterile container and sent to a laboratory for analysis. Tests performed on blood specimens can include checking for infections, measuring blood cell counts, and evaluating organ function. Accurate results from these tests are crucial for effective treatment and patient care.