Cardiologists are doctors who specialize in the diagnosis, prevention and treatment of conditions related to the heart and blood vessels. A patient may be referred to a cardiologist if he experiences symptoms like chest pains, shortness of breath, dizziness, or high blood pressure. The physician will then evaluate your symptoms, take your health and family history and your weight. The cardiologist may order additional diagnostic tests, such as an echocardiogram, X-ray or blood tests. If necessary, the cardiologist may also call for a cardiac catheterization - a procedure in which a small tube is inserted into or near the heart that can take pictures of the heart's activity, or relieve blockage. Once determining whether there is a heart condition, a cardiologist will treat a patient through cholesterol management, cardiac rehabilitation, and fitness. If surgical intervention is required, like open-heart surgery, a cardiologist will make that determination, but a cardiothoracic surgeon will perform the procedure.

An internist is a physician who focuses on the diagnosis and treatment of conditions that affect the adult population—both acute and chronic.These doctors are often who adults see as their primary physicians because they treat a broad range of illnesses that do not require surgical or specialist interventions. They also work to help a patient maintain optimal health in order to prevent the onset of disease.In addition to treating the common cold and flu, internists also treat chronic diseases like diabetes and heart disease.

An interventional cardiologist has the same training as a cardiologist and they're well-versed in all types of heart disease and how to diagnose heart problems. The difference is that interventional cardiologists have additional expertise and training on specific interventional treatments for heart disease, such as angioplasties and stents. These methods use catheterization, which reduces recovery time as well as scarring after surgery.

A nephrologist is a physician who is specially trained to diagnose and treat conditions affecting the kidneys or renal system. A nephrologist will determine through urine analysis, blood test, X-ray, sonogram, or kidney biopsy how well the kidneys are functioning and will then prescribe a special diet and exercise program, medication or dialysis - a process by which a machine filters the blood when the kidney is no longer capable of doing so.

Nuclear medicine specialists are doctors who have extensive training in the use of nuclear substances, like radiation, to diagnose and treat certain illnesses.These specialists perform diagnostic tests in which a small amount of a radioactive substance is injected into a vein, inhaled or taken orally by the patient. The radioactive substance then enables the nuclear medicine specialist to use a scanner to detect the radiation level in the part of the body being examined in order to create an image of it with a computer. The images tell the physician whether there are abnormal changes in metabolism which indicate whether a disease or injury is present. These tests are often used to detect cancer.In addition to detecting cancer, substances like radioactive iodine can be either injected into the blood stream or taken orally to fight cancer and other diseases. After being ingested, the substance is absorbed by the thyroid gland and abnormal thyroid tissues are destroyed.