Neurology is the study of disorders of the nervous system. A neurologist is a physician who diagnoses and treats nervous system disorders of the brain, spinal cord and nerves. This specialist deals with problems related to brain disease, disorders of the brain, spinal cord, and the nerves, and the blood vessels that provide circulation to these organs. A neurologist also treats specific diseases such as Bell’s palsy, cerebellar ataxia and meningitis.

Physicians in this specialty treat patients suffering from numerous diseases and illnesses, but some of the most common are stroke, Guillain-Barré syndrome, brain tumor, migraine, meningitis, seizure, Parkinson's disease, epilepsy, cerebral palsy, coma, multiple sclerosis, Alzheimer's disease, cluster headache, ischemic stroke, encephalitis, encephalopathy, botulism, chorea, Lou Gehrig's disease, and ataxia.

Once properly diagnosed, practitioners can perform numerous procedures on patients including Electroconvulsive therapy and Electroencephalogram (EEG).

To diagnose patients with possible illnesses and diseases, specialists will often perform one of many tests including CAT Scan of the Brain, CT Scan of the Brain, MRI Scan of the Brain, MRI Scan of the Spine, Magnetic Resonance Imaging (MRI), Computed Axial Tomography (CT or CAT Scan), Myelogram, Spinal Tap, Lumbar Puncture (LP), Electromyography (EMG), Myelography, Positron Emission Tomography (PET Scan), Spinal Puncture, Nerve Conduction Velocity (NCV), Electroencephalography, Cerebral Angiogram, Electronystagmography (ENG), Ocular Pressures, CSF Collection, and Myogram.

Doctor density varies by specialty and location. Illinois has 528 practicing neurologists. Broken out by city, neurology doctor density in Alton is 2, in Aurora is 10, in Belleville is 4, in Berwyn is 5, in Bloomington is 11, in Blue Island is 3, in Calumet City is 2, in Canton is 2, in Carbondale is 1, in Carlinville is 2, in Centralia is 2, in Champaign is 6, in Charleston is 1, in Chicago is 214, in Chicago Heights is 6, in Clinton is 1, in Crest Hill is 1, in Crystal Lake is 6, in Danville is 6, in Darien is 1, in Decatur is 6, in Dekalb is 3, in Des Plaines is 6, in Effingham is 1, in Elgin is 6, in Elk Grove Village is 7, in Elmhurst is 3, in Evanston is 18, in Freeport is 2, in Galesburg is 4, in Geneva is 4, in Granite City is 2, in Harvard is 1, in Harvey is 1, in Herrin is 2, in Highland Park is 8, in Hillsboro is 1, in Hinsdale is 6, in Jacksonville is 1, in Jerseyville is 1, in Joliet is 11, in Kankakee is 2, in Kewanee is 1, in Lake Bluff is 2, in Lincoln is 1, in Litchfield is 1, in Lockport is 1, in Loves Park is 1, in Macomb is 2, in Marion is 1, in Martinsville is 2, in Mattoon is 3, in Mchenry is 2, in Melrose Park is 5, in Moline is 5, in Morris is 2, in Mount Vernon is 1, in Naperville is 13, in Nashville is 3, in Niles is 6, in North Chicago is 5, in Northbrook is 5, in Oak Park is 8, in Oakbrook Terrace is 3, in Olney is 1, in Olympia Fields is 8, in Orland Park is 7, in Ottawa is 1, in Palos Heights is 12, in Park Ridge is 11, in Pekin is 4, in Peoria is 30, in Peru is 1, in Quincy is 4, in Rantoul is 1, in Red Bud is 1, in Rock Island is 2, in Rockford is 17, in Rushville is 1, in Schaumburg is 5, in Springfield is 23, in Staunton is 1, in Sterling is 1, in Swansea is 1, in Urbana is 7, in Vernon Hills is 2, in Warrenville is 9, in Washington is 2, in Waterloo is 1, in Watseka is 1, in Waukegan is 2, in West Dundee is 1, in Westmont is 4, in Wheaton is 4, in Wheeling is 1, in Wilmette is 6, in Woodridge is 2, in Woodstock is 2, in Yorkville is 1, and in Zion is 1.

Most people think that Chicago, because of its size and popularity, is Illinois’ capital city, but that distinction belongs to Springfield, home of the Abraham Lincoln Museum. Illinois has hundreds of museums, numerous yearly art and ethnic festivals, a lakeshore bordering Lake Michigan, and the many national forests and parks that offers visitors camping, horseback riding, biking, kayaking, and fishing. Chicago is home to the Sears Tower, the Shedd Aquarium, the Art Institute of Chicago, the Adler Planetarium, the Museum of Science and Industry, and other cultural opportunities and restaurants in the Navy Pier area.

According to 2005 Census estimates, Illinois has a population of 12,763,371. Of this population, 3,172,677 are under the age of 18 and 1,523,937 are at or above the age of 65.