An addiction medicine specialist is a doctor who treats patients with addictions to substances like drugs and alcohol, or in some cases, behaviors like gambling. Many of these specialists also treat the diseases that stem from these addictions. These physicians are specially trained to prevent and treat the disease of addiction via psychiatric means, or other fields of medicine like family or internal medicine.

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.

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 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.

An ophthalmologist has the training to do much more than just prescribe glasses. They are physicians specially trained to diagnose and treat disorders of the eyes and vision. These doctors are experts on the complicated anatomy of the eye and are trained to treat eye diseases through both medical and surgical methods.Some common conditions that ophthalmologists treat are cataracts, glaucoma, strabismus, diabetic retinopathy, macular degeneration and amblyopia. In addition, ophthalmologists can provide prescriptions for eye glasses and contact lenses and perform LASIK surgery and other corrective surgeries for refractive errors like myopia (near-sightedness), hyperopia (far-sightedness), astigmatism and presbyopia.

A urologist is a physician who specializes in diagnosing and treating conditions affecting the male reproductive system, as well as the urinary tracts of both males and females. These doctors cover the kidneys, ureter, urinary bladder, adrenal glands, urethra, and the male reproductive organs which include the testes, epididymis, vas deferens, seminal vesicles, prostate and penis. Some common disorders that urologists treat are urinary tract infections (UTI), stress incontinence, benign prostatic hyperplasia, kidney stones, erectile dysfunction, kidney cancer, prostate cancer, testicular cancer, and cystitis. These urological specialists also perform vasectomies and vasectomy reversals.