This list covers 15 medical specialties, running alphabetically from “Obstetrics” to “Otorhinolaryngology.” These fields span care for pregnant mothers, cancer patients, eye and ear conditions, jaw and facial injuries, and general bone and joint health. Doctors and specialists use these areas of practice every day to diagnose problems, plan treatments, and guide patients through recovery.

Medical specialties are focused branches of medicine where doctors build deep expertise in one part of the body or one type of care. The letter “O” happens to hold an unusually large cluster of them, since so many specialty names in English trace back to Greek roots like “ophthalmos” (eye) and “os” or “osteon” (bone), giving us terms like ophthalmology and osteopathic medicine.

Below you’ll find the table with the medical specialty and its description.

Medical specialty: the official name of the field, so you can quickly spot the one you’re looking for or compare it with similar terms.

Description: a plain-language explanation of what the specialty treats and what a doctor in that field actually does for patients.

Medical specialties

Medical specialty
Obstetrics
Occupational Medicine
Oncology
Ophthalmology
Optometry
Oral and Maxillofacial Surgery
Oral Medicine
Oral Pathology
Orthodontics
Orthopedic Surgery
Orthoptics
Osteopathic Medicine
Otolaryngology
Otology
Otorhinolaryngology

Descriptions

Obstetrics
The branch of medicine focused on pregnancy, childbirth, and the postpartum period, covering prenatal care, labor management, and recovery for mothers and newborns.
Occupational Medicine
A specialty focused on preventing and treating illnesses and injuries related to the workplace, helping keep employees healthy, safe, and able to perform their jobs.
Oncology
The study and treatment of cancer, including diagnosis, chemotherapy, and coordinating care for patients through every stage of the disease.
Ophthalmology
The medical and surgical specialty dealing with the eyes, treating conditions like cataracts, glaucoma, and vision problems, and performing eye surgery.
Optometry
A specialty focused on examining eyes for vision problems, prescribing corrective lenses, and detecting eye diseases, often serving as a first point of eye care.
Oral and Maxillofacial Surgery
A surgical specialty treating diseases, injuries, and defects of the mouth, jaw, face, and neck, including corrective jaw surgery and facial trauma repair.
Oral Medicine
A specialty focused on diagnosing and managing diseases affecting the mouth and jaw that are not treated with surgery, such as ulcers and chronic pain conditions.
Oral Pathology
The study of diseases affecting the mouth and jaw tissues, using lab analysis to diagnose conditions ranging from infections to oral cancers.
Orthodontics
A dental specialty focused on correcting misaligned teeth and jaws using braces, aligners, and other devices to improve bite and appearance.
Orthopedic Surgery
The branch of medicine dealing with the musculoskeletal system, treating bone fractures, joint problems, and sports injuries through surgery and rehabilitation.
Orthoptics
A specialty focused on diagnosing and treating eye movement disorders and problems with binocular vision, such as double vision and lazy eye.
Osteopathic Medicine
A holistic approach to medicine that combines standard medical training with hands-on manipulation techniques to treat the body as an interconnected whole.
Otolaryngology
Also known as ENT, this specialty treats disorders of the ear, nose, and throat, including hearing loss, sinus problems, and voice disorders.
Otology
A specialty focused specifically on diseases and disorders of the ear, including hearing loss, balance issues, and ear infections.
Otorhinolaryngology
The formal medical term for ear, nose, and throat (ENT) medicine, covering surgical and nonsurgical treatment of related conditions.
If you think there is a missing term, let us know using the contact form.