An allergic disease results with the immune system that normally protects the body from harmful invaders such as viruses or bacteria , incorrectly recognizes a harmless substance such as pollen as a target for the immune system to attack. The reaction can produce undesirable and sometimes, life-threatening symptoms. To train as an allergist a physician who has completed an internal medicine or pediatric fellowship completes 3 years of additional training to identify the factors that initiate allergic diseases, and help patients to prevent or treat these conditions. Cardiovascular Disease - To become a cardiologist, a physician trained in internal medicine completes 4 to 5 years of additional training. Cardiologists specialize in diseases of the heart and vascular system .
Cardiologists treat heart attacks, heart failure, and abnormal heart rhythms.
They perform heart catheterization by which a catheter is inserted into a blood vessel going to the heart, in order to obtain information about the heart and the arteries supplying it. They also perform balloon angioplasty as a treatment for narrowed arteries in which a balloon-tipped catheter is inserted into an artery, usually the ones supplying the heart, to widen the vessel wall, thus increasing blood flow to a given area. After evaluation, they decide if heart surgery or other surgical procedures are needed. Endocrinology - To become an endocrinologist, a physician trained in internal medicine completes 2 to 3 years of additional training in the diagnosis and treatment of diseases associated with internal glandular secretions or hormones. Diseases addressed by this specialty include diabetes , diseases of the thyroid gland, cholesterol disorders, hypertension, osteoporosis , adrenal and pituitary glands, hormonal disorders causing infertility, low blood sugar, abnormal development, low blood pressure and certain weight problems.