Glossary of medical specialties and healthcare terms
Specialty names come mostly from Greek and Latin, which is why they rarely tell you what the doctor actually does. This glossary translates them into plain language, along with the insurance and healthcare terms that come up when booking an appointment.
Specialties we cover in detail
Each of these links to a full guide explaining what the specialty treats and when to see one.
- Cardiologist
- A doctor who treats the heart and blood vessels, including chest pain, palpitations, high blood pressure, and heart failure.
- Dermatologist
- A doctor who treats the skin, hair, and nails, including rashes, acne, eczema, hair loss, and skin cancer screening.
- ENT (Otolaryngologist)
- A doctor who treats the ears, nose, throat, and sinuses. The full name is otolaryngologist, but almost everyone says ENT.
- Gastroenterologist
- A doctor who treats the digestive system, including the esophagus, stomach, intestines, liver, gallbladder, and pancreas.
- Neurologist
- A doctor who treats the brain, spinal cord, and nerves, including migraine, seizures, numbness, tremor, and memory problems.
- OB-GYN
- An obstetrician-gynecologist. Obstetrics covers pregnancy and childbirth; gynecology covers the female reproductive system.
- Ophthalmologist
- A medical eye doctor who can prescribe medication and perform eye surgery. Distinct from an optometrist.
- Orthopedist
- A doctor who treats bones, joints, muscles, tendons, and ligaments. Also called an orthopedic surgeon, though most care is non-surgical.
- Primary Care Physician (PCP)
- A generalist who treats everyday illness, manages chronic conditions, provides preventive care, and refers to specialists when needed.
- Psychiatrist
- A medical doctor specializing in mental health who can diagnose conditions and prescribe medication.
- Pulmonologist
- A doctor who treats the lungs and breathing, including asthma, COPD, chronic cough, and sleep-related breathing disorders.
- Urologist
- A doctor who treats the urinary tract in all patients and the male reproductive system.
Other specialties and clinical roles
You may be referred to these, though we do not yet have dedicated guides for them.
- Allergist / Immunologist
- Treats allergies, asthma, and immune system disorders.
- Anesthesiologist
- Manages sedation, pain control, and monitoring during surgery.
- Endocrinologist
- Treats hormone-related conditions, including diabetes and thyroid disorders.
- Geriatrician
- A physician specializing in the care of older adults.
- Hematologist
- Treats blood disorders such as anemia and clotting problems.
- Hospitalist
- A physician who cares for patients specifically during a hospital stay.
- Nephrologist
- Treats kidney disease and manages dialysis.
- Nurse Practitioner (NP)
- An advanced practice nurse who can diagnose, treat, and in most states prescribe medication.
- Oncologist
- Treats cancer, including chemotherapy and other systemic therapies.
- Optometrist
- Examines eyes and prescribes glasses and contact lenses. Not a medical doctor; see an ophthalmologist for eye disease.
- Pediatrician
- A primary care physician for infants, children, and adolescents.
- Physician Assistant (PA)
- A licensed clinician who diagnoses and treats patients while working with a supervising physician.
- Physiatrist
- Specializes in physical medicine and rehabilitation, focusing on restoring function after injury or illness.
- Podiatrist
- Treats conditions of the foot and ankle.
- Psychologist
- Provides talk therapy and psychological testing. Generally does not prescribe medication.
- Radiologist
- Interprets imaging such as X-rays, CT scans, and MRIs. You usually do not meet them directly.
- Rheumatologist
- Treats inflammatory and autoimmune conditions affecting joints and connective tissue, such as rheumatoid arthritis and lupus.
Healthcare and insurance terms
- Acute
- A symptom or condition that starts suddenly and is usually short-lived. The opposite of chronic.
- Chronic
- A condition lasting a long time, generally three months or more, often managed rather than cured.
- Copay
- A fixed amount you pay for a covered service. Specialist copays are typically higher than primary care copays.
- Deductible
- The amount you pay out of pocket each year before insurance begins covering costs.
- Differential diagnosis
- The list of possible causes a doctor considers before narrowing down to a single explanation.
- In-network
- A provider who has an agreement with your insurance plan, usually meaning lower cost to you.
- Prior authorization
- Approval your insurer requires before covering certain tests, procedures, or medications.
- Referral
- A recommendation from one doctor to another, often required by insurance before a specialist visit is covered.
- Triage
- The process of sorting patients by urgency so the most time-critical cases are treated first.
- Urgent care
- A walk-in clinic for problems that need same-day attention but are not life-threatening.
This is not medical advice. These definitions are educational only and do not diagnose conditions. In an emergency, call 911. Read our full medical disclaimer.
Curious where medical ethics came from? Read our guide to the Hippocratic Oath.