Adolescent specialists are doctors who have advanced training in the health issues that adolescents face. These physicians deal with issues like the onset of puberty, reproductive health, eating disorders, irregular periods, mood changes, drugs and pressures from home and school. For girls entering adulthood, adolescent specialists can act as both pediatrician and gynecologist, so they only have to see one doctor for all their needs.

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.

Also sometimes referred to as intensivists, critical care specialists are physicians with specialized training in the diagnosis and management of life-threatening conditions, such as those that affect vital organs like the heart and lungs, those that make breathing difficult or impossible, and those that affect entire organ systems, like the renal system. Critical care specialists are typically found in a hospital's intensive care unit where they monitor patients with life-threatening conditions and make determinations as to the best course of treatment.

An endocrinologist is a physician with extensive training in understanding, diagnosing and treating conditions related to the endocrine system. The endocrine system regulates the balance of hormones. Conditions of the endocrine system involve an over-abundance, or deficiency of a certain hormone. While there is a range when it comes to the amount of a hormone that is deemed normal in a human, these specialists determine whether a person's amount of hormone is indicative of a health concern.

A family practitioner is a doctor who specializes in caring for people of all ages, at all stages of life. Rather than focusing on the treatment of one disease or patient population, family practitioners are often the doctors that people see for their everyday ailments, like cold and flu or respiratory infections, and health screenings. When necessary, family practitioners will provide referrals for conditions that require the expertise of another specialist.The doctors may also provide physicals, inoculations, prenatal care, treat chronic diseases, like diabetes and asthma, and provide advice on disease prevention.

A gastroenterologist is a specialist in diagnosis and treatment of conditions involving the digestive/gastrointestinal (GI) tract. These doctors are experts on how food moves through the digestive system and is chemically broken down, with nutrients being absorbed and waste excreted. You might see this kind of doctor if you are experiencing any number of stomach issues, some of which might be severe diarrhea, irritable bowel syndrome, hemorrhoids, ulcers, acid reflux, Crohn's disease and more.

An infectious disease specialist has specialized training in the diagnosis and treatment of contagious diseases.Infectious diseases, also known as contagious or transmissible diseases, are those that stem from pathogen from a host organism. These infections may spread to other carriers through physical touch, airborne inhalation, bodily fluids or contaminated foods.Infectious disease specialists identify whether the disease is caused by bacteria, a virus, a fungus or a parasite often through blood tests and then determine what course of treatment, if any, is necessary.

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.

A pediatric specialist is a physician who has extensive training in the diagnosis and treatment of specific conditions in children. These doctors are specialists in one particular therapy area, such as dermatology, pulmonology, surgery, or ophthalmology, in addition to being pediatricians. Pediatric specialists are who parents would take their children to when they are diagnosed with a condition requiring specialist treatment not provided by their pediatrician or primary care provider. While specialists in any area are qualified to treat children as well as adults, pediatric specialists have specific training in the way diseases affect children who are still growing and have different emotional needs than adults.

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 neurologist is a physician who diagnoses and treats disorders of the nervous system which is comprised of the brain, spinal cord and nerves. These doctors do not perform surgery, but refer patients to neurological surgeons when they determine that surgical intervention is necessary. Some of the conditions that neurologists diagnose and treat are epilepsy, aneurysms, hydrocephalus, Parkinson's disease, multiple sclerosis, stroke, spinal disc herniation, and spinal disease. In addition to using diagnostic tests like MRI, CT scans, EEG and EMG, neurologists also employ neurological testing to gauge muscle strength and movement, balance, reflexes, sensation, memory, speech, and other cognitive abilities.

An obstetrician & gynecologist, or OB/GYN, is a physician who cares for women throughout their pregnancies, straight through to the delivery of their baby (obstetrician). They also specialize in annual care, as well as the diagnosis and treatment of disorders of the female reproductive system (gynecologist). Many physicians specialize in both of these fields in order to provide complete overall health services to women at every stage of life.

A pediatrician is a doctor who specializes in the regular care of children, as well as the diagnosis and treatment of illness in children. Young patients are often more complicated to treat because they are still growing and developing. While pediatricians may sub-specialize in specific therapy areas like oncology, surgery, ophthalmology, and anesthesiology, in general, pediatricians provide services like vaccinations, health exams, and treatment of common ailments and injuries. In addition, pediatricians are trained to handle the complex emotional and behavioral issues faced by children, especially during puberty. Pediatricians normally see their patients from birth until the age of 18, although some may agree to treat patients into their early 20s, if requested.

A psychiatrist is a doctor with specific training in the diagnosis and treatment of mental illness. He or she can not only provide the counseling necessary to both diagnose and treat a patient, but can also prescribe medication when needed. In some cases, a psychiatrist will only provide the medication and the counseling will be provided by another healthcare specialist, like a certified counselor or psychologist. Like other doctors, psychiatrists employ diagnostic tools like CT scans and MRI in order to observe the structure and function of a patient's brain. Once a diagnosis is made, these specialists may use behavior or cognitive therapy in order to address the patient's condition, or a multitude of other types of therapy, in conjunction with or in place of medication.

A pulmonologist is a physician who specializes in the diagnosis and treatment of conditions related to the lungs and respiratory tract.These specialists are similar to critical care specialists in that their patients often require mechanical ventilation to assist their breathing.Pulmonologists diagnose and treat patients with conditions such as asthma, cystic fibrosis, asbestosis, pulmonary fibrosis, lung cancer, COPD, and emphysema. Exposure and inhalation of certain toxic substances may also warrant the services of a pulmonologist.Some of the tools and tests pulmonologists use to diagnose a patient are a stethoscope in order to listen for abnormal breathing sounds, chest X-rays, CT scans, blood tests, bronchoscopy, and polysomnography.