Comorbidity (say "koh-mor-BID-uh-tee") means that a person has
two or more diseases at the same time. These are usually long-
term (chronic) diseases that need treatment for a lifetime.
Examples of comorbidities include having both high blood
pressure and diabetes, or having high cholesterol, heart
failure, and diabetes. Comorbidities can change treatment
options. One disease can make another disease worse, and the
total effect of all the diseases may be more than each one on
its own.