A plastic surgery specialist is a physician with extensive training in the execution of plastic surgery procedures.
Plastic surgery is the use of surgical procedures to rebuild or reshape injured or misshapen body parts. Congenital defects, such as a cleft lip or palate, can be corrected by a plastic surgery specialist. Injuries sustained during auto accidents also may require the services of a plastic surgery specialist. These procedures fall under the category of reconstructive plastic surgery.
The other category of plastic surgery is cosmetic plastic surgery. Plastic surgery specialists often perform procedures like breast augmentation, face lifts, tummy tucks, liposuction, and lip injection as elective surgeries for patients who wish to make aesthetic improvements.

A hematology specialist is an expert in disorders of the blood, the blood forming organs and bone marrow. These doctors diagnose, treat and work to prevent diseases that affect the production of blood and its components, as well as the ability of the blood to perform its many functions, such as coagulation and carrying oxygen to the lungs and tissue.
Hematologists diagnose and treat blood disorders, such as anemia, hemophilia, leukemia, sickle cell anemia, deep vein thrombosis and pulmonary embolism.
Depending on the condition, hematology specialists may treat a patient with a blood transfusion, stem cell transplantation, bone marrow transplant, radiotherapy, anticoagulation therapy or medication.

An otolaryngologist is more commonly referred to as an ENT, someone that can treat medical issues you may be having with you ears, nose, or throat. This is a physician who is specially trained to diagnose and treat conditions of the ear, nose, sinuses, larynx (voice box), mouth, throat, head, and neck. These doctors treat patients through both medical and surgical means. For instance, an otolaryngologist may treat an obstruction of the nasal passage, caused by malformation of the nose, through rhinoplasty.

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 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.