Nutrition basics
Learning Center
Cholesterol ratio or non-HDL cholesterol: Which is most important?
Non-HDL cholesterol may be more important than cholesterol ratio.
Cholesterol test
Measuring the amount of cholesterol and triglycerides in your blood can help predict your risk of blocked arteries in your heart and brain.
Cholesterol test kits: Are they accurate?
Home cholesterol test kits are often as accurate as the test a health care professional uses, but the quality of results can depend on how well you follow the directions for the test.
Circumcision (male)
Learn about the benefits and risks of surgery to remove the skin that covers the tip of the penis.
Coconut water: Is it super hydrating?
This drink is promoted as "super hydrating." But is it really any better than plain water?
Coffee and health: What does the research say?
Has coffee gotten a bum rap? Can it be part of a healthy diet?
Complete blood count (CBC)
Learn what to expect from having this common blood test, why it's done and how to prepare.
Coronary angiogram
Learn more about this heart disease test that uses X-ray imaging to see the heart's blood vessels.
Coronary calcium scan
This heart CT test can show calcium deposits in the blood vessels. Know how the findings relate to your heart disease risk.
Cryotherapy for prostate cancer
Find out how very cold temperatures are used to freeze tissue and treat prostate cancer. Learn about the side effects and potential benefits of cryotherapy.