That depends on exactly what you mean.
Neurologists specialize in non-surgical problems of the brain and nervous system such as seizures and headaches.
Neurosurgeons do surgery on the brain and nervous system including the spine.
Ear nose and throat specialists (aka otolargyngologists) specialise in those organ systems.
A flag specialist is called a vexillologist.
Such a specialist is known by the title of podiatrist or chiropodist.
A vocal specialist is called a Speech Therapist
A climatologist
A. Pediatricians
urologist
Pneumocologist
A "Roundsman"
no
skullologist
Gastroenterologists
secatarist