Blood work refers to a series of tests performed on a sample of blood to assess a person's health. These tests can measure various components, including red blood cells, white blood cells, platelets, and hemoglobin. Blood work helps diagnose conditions, monitor health, and evaluate the effectiveness of treatments. Common types of blood tests include complete blood count (CBC), which provides information about blood cells, and blood chemistry tests, which measure substances like glucose and electrolytes. Doctors often use blood work to screen for diseases, check organ function, and determine overall health status.