Phlebotomy Online Diploma Programs: Phlebotomy is the act of drawing blood either for testing or transfusion. It is a skill employed by physicians and many professionals in allied health fields, including nurses, medical assistants, paramedics, and clinical laboratory scientists. Health care is a rapidly expanding industry, and a new professional, the certified phlebotomist, helps to reduce the workload of doctors and nurses by focusing exclusively on blood collection, particularly in hospitals and blood drives.