A dermatologist is a medical doctor who diagnoses and treats conditions of the skin, hair, nails, and mucous membranes. That scope is broader than most people expect. Beyond clearing up acne or examining a suspicious mole, dermatologists perform surgeries, manage chronic inflammatory diseases, run allergy workups, and provide cosmetic treatments like laser therapy and injectable fillers.
Conditions Dermatologists Treat
Skin is the body’s largest organ, and the list of things that can go wrong with it is long. The most common reasons people end up in a dermatologist’s office include acne, eczema (patches of red, inflamed, itchy skin), psoriasis (scaly red plaques that tend to flare and recede), hives, skin infections, and skin cancer. But dermatologists also handle hair loss, nail disorders, dandruff, warts, rosacea, and allergic reactions that show up on the skin.
Many of these conditions overlap with other specialties. A dermatologist might work alongside an allergist to pin down what’s triggering chronic hives, or coordinate with a rheumatologist when psoriasis comes with joint pain. Some conditions they treat are straightforward and resolve quickly. Others, like eczema and psoriasis, are chronic and require long-term management plans that get adjusted over months or years.
Skin Cancer Screening
One of the most important things a dermatologist does is check your skin for cancer. During a full-body skin exam, you’ll change into a gown and the doctor will look at your entire body, including your scalp, behind your ears, between your fingers, your feet, and your buttocks. The whole process takes about 10 to 15 minutes.
To get a closer look at specific moles or spots, dermatologists use a dermoscope, a handheld device that combines light and magnification to reveal details in the outer layer of skin invisible to the naked eye. A standard dermoscope magnifies the view by about 10 times, while video versions can reach 70 to 100 times magnification. The device’s light is designed to illuminate the skin without glare bouncing off dry or oily patches, making subtle color patterns and structures easier to evaluate. Dermatologists use it to identify potentially cancerous growths, including melanoma, basal cell carcinoma, and other skin cancers, but also non-cancerous issues like warts, hair loss conditions, and even scabies.
If a spot looks concerning, the next step is usually a biopsy. The dermatologist removes a small sample of tissue (or sometimes the entire spot) and sends it to a lab for analysis. This is the only way to confirm whether something is cancerous.
Between appointments, you can monitor your own skin using the ABCDE framework for melanoma: asymmetry (one half of a mole looks different from the other), border irregularity, uneven color, diameter larger than a pencil eraser, and evolving size, shape, or color over weeks or months.
Surgical Procedures
Dermatologists are trained surgeons, though their procedures tend to be smaller in scale than what you’d see in an operating room. Common surgeries include mole removal, skin cyst removal, scar revision, and skin biopsies. Most of these are done in-office under local anesthesia.
The most specialized surgical procedure in dermatology is Mohs surgery, a technique used for skin cancers in areas where preserving healthy tissue matters, like the face. The surgeon removes cancer one thin layer at a time, examining each layer under a microscope before deciding whether to take more. This approach has the highest cure rate for common skin cancers while removing as little surrounding skin as possible. Mohs surgery is its own sub-specialty, requiring additional fellowship training beyond residency.
Cosmetic Treatments
A significant part of modern dermatology is cosmetic. Dermatologists perform injectable treatments to smooth wrinkles and restore facial volume, laser treatments to reduce scars, remove tattoos, and eliminate unwanted hair, and chemical peels to improve skin texture and tone. They also treat age spots, spider veins, and stretch marks.
What separates a dermatologist from other providers offering these same treatments is medical training. A dermatologist understands the underlying biology of skin, can recognize when a “cosmetic” concern is actually a medical one, and is equipped to handle complications if they arise. Cosmetic procedures done by dermatologists are typically not covered by insurance.
Training and Certification
Becoming a dermatologist requires four years of college, four years of medical school, and at least one year of general clinical training, followed by a three-year dermatology residency. That’s a minimum of 12 years of education and training after high school. Dermatology residencies are among the most competitive in medicine.
After residency, dermatologists can become board certified through the American Board of Dermatology. Certification requires graduating from an accredited medical school, completing an accredited residency, passing a series of exams (four written modules plus a practical exam), and holding an unrestricted medical license. Board certification signals that a dermatologist has met a national standard of knowledge and competence.
Some dermatologists pursue additional fellowship training in one of three recognized sub-specialties: dermatopathology (reading skin biopsies under a microscope to diagnose disease), Mohs micrographic surgery, or pediatric dermatology. Each adds one to two years of focused training.
When a Dermatologist Visit Makes Sense
You don’t need a dramatic symptom to justify seeing a dermatologist. If you’ve been using over-the-counter products for acne, dry skin, or a rash and nothing is improving, a dermatologist can identify what’s actually going on. Many people spend months treating what they assume is dry skin or an allergic reaction when it’s actually a chronic condition like eczema or psoriasis that responds to specific prescription therapies.
A few situations do warrant a faster visit. Any mole or patch of skin that has changed in color, size, shape, or feel should be evaluated. Hives or rashes that persist for weeks, especially with no obvious trigger, can signal an underlying issue that needs a proper workup. And persistent, unexplained hair loss or nail changes can sometimes point to systemic health problems a dermatologist is trained to recognize.