Definition: A comorbidity is a disease or condition that coexists with a primary disease but also stands on it's own as a specific disease. For example, someone can have hypertension (high blood pressure) and not have diabetes. But on the other hand, someone with diabetes very often has hypertension too. So hypertension is a common comorbidity of diabetes.
Other common comorbidities of diabetes are hyperlipidemia, cardiovascular disease, kidney disease, nonalcoholic fatty liver disease, and obesity.
Sources:
Nonalcoholic Steatohepatitis. Retrieved February 7, 2008, from National Digestive Diseases Information Clearinghouse (NDDIC) Web site: http://digestive.niddk.nih.gov/ddiseases/pubs/nash

