Internal medicine refers to the specialty of prevention, diagnosis, and treatment of all adult diseases, not just those that may involve internal organs. Typically called internists, we typically care for back pains, arthritis, hypertension, coronary artery disease, diabetes, high cholesterol, depression, asthma, allergies, rashes, fibromyalgia, osteoporosis and a multitude of other problems. Every internal medicine physician will have a threshold, whereby their comfort level in caring for a specific ailment, symptom, or disease is exceeded leading to a referral to a specialist. Whereas they often perform simple procedures, like electrocardiograms, skin incisions, and joint injections, internal medicine physicians will refer larger procedures to surgeons or other specialists. This training now requires 3 years of training after medical school and there are specialty board certifications.