General surgery can be performed on almost any area of the body. A general surgeon is a physician who performs surgery and provides preoperative, operative, and postoperative care to surgical patients. This surgeon can treat diseases, injuries or deformities by surgery or minimally invasive techniques, such as endoscopy, where a tiny scope is used to view internal organs or structures. The endoscope can be used during operating procedures, or before surgery, to diagnose, assess and treat problem areas.

Physicians in this specialty treat patients suffering from numerous diseases and illnesses, but some of the most common are breast disease, thyroid disorders, hernia, breast cancer, Crohn's Disease, cystic fibrosis, Cirrhosis, Hepatitis, lymphoma, Chronic renal failure, Morbid obesity, Adhesions, Colorectal cancer, Hirschsprung's disease, Volvulus, Thyroid cancer, Kidney cancer, Metastatic disease, Toxic megacolon, and Meckel's diverticulum.

Once properly diagnosed, practitioners can perform numerous procedures on patients including microsurgery, mastectomy, laser surgery, Minimally Invasive Surgery, breast reconstruction, breast surgery, thyroid surgery, Laparoscopic Surgery, da Vinci Surgical System, Bypass Surgery, robotic surgery, Resection, Liver transplant, Whipple procedure, Kidney transplant, Bariatric surgery, Appendectomy, Cholecystectomy, cryosurgery, and abdominal surgery.

To diagnose patients with possible illnesses and diseases, specialists will often perform one of many tests including endoscopy, Magnetic Resonance Imaging (MRI), x-ray, Computed Axial Tomography (CT or CAT Scan), Electrocardiogram (ECG or EKG), biopsy, Cardiac Stress Test, Lower GI (Barium Enema), Upper GI (Barium Swallow), and fecal occult bloodtest.

Doctor density varies by specialty and location. Illinois has 1,118 practicing general surgeons. Broken out by city, general surgery doctor density in Alton is 9, in Anna is 2, in Aurora is 19, in Belleville is 11, in Berwyn is 9, in Bloomington is 19, in Blue Island is 6, in Breese is 2, in Calumet City is 1, in Canton is 2, in Carbondale is 11, in Carlinville is 3, in Centralia is 4, in Champaign is 12, in Chester is 1, in Chicago is 335, in Chicago Heights is 3, in Clinton is 3, in Crystal Lake is 5, in Danville is 14, in Decatur is 14, in Dekalb is 5, in Des Plaines is 12, in Dixon is 3, in Effingham is 7, in Elgin is 15, in Elmhurst is 16, in Eureka is 4, in Evanston is 21, in Fairfield is 1, in Freeport is 5, in Galesburg is 8, in Geneseo is 3, in Geneva is 14, in Granite City is 7, in Greenville is 1, in Harrisburg is 3, in Harvard is 3, in Harvey is 8, in Havana is 1, in Herrin is 12, in Highland is 3, in Highland Park is 9, in Jacksonville is 6, in Joliet is 26, in Kankakee is 9, in Kewanee is 2, in Lake Forest is 5, in Litchfield is 1, in Macomb is 3, in Marion is 9, in Mattoon is 8, in Mchenry is 4, in Mendota is 2, in Moline is 13, in Monmouth is 2, in Morris is 11, in Mount Carmel is 2, in Mount Vernon is 6, in Murphysboro is 1, in Naperville is 31, in Nashville is 1, in Normal is 2, in North Chicago is 3, in Oak Forest is 1, in Oakbrook Terrace is 4, in Ottawa is 4, in Palos Heights is 6, in Park Ridge is 14, in Pekin is 3, in Peoria is 46, in Peru is 4, in Pinckneyville is 3, in Plano is 1, in Pontiac is 5, in Quincy is 4, in Red Bud is 2, in Rochelle is 2, in Rock Island is 5, in Rockford is 23, in Sandwich is 3, in Shelbyville is 3, in Silvis is 3, in Sparta is 1, in Springfield is 43, in Staunton is 2, in Sterling is 3, in Streator is 3, in Sycamore is 2, in Urbana is 18, in Warrenville is 1, in Washington is 1, in Waterloo is 2, in Watseka is 1, in Waukegan is 2, in Wheaton is 12, in Wood Dale is 1, in Woodstock is 5, in Yorkville is 1, and in Zion is 2.

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.