Medical diagnosis is the process by which a healthcare professional identifies the nature and cause of a disease or ailment based on collected information. This systematic assessment involves gathering patient history, evaluating physical signs, and interpreting data from various laboratory and imaging tests, such as blood panels or radiographic scans. The process often requires forming a differential diagnosis—a list of potential conditions that could be responsible—which is then narrowed down through clinical reasoning and methodical exclusion of possibilities. An accurate diagnosis is critical as it guides the selection of appropriate treatment strategies and preventative measures necessary for patient care.