Atorvastatin is used for:

Lowering high cholesterol and triglycerides in certain patients. It also increases high-density lipoprotein (HDL, "good") cholesterol levels. It is used along with an appropriate diet. It is used in certain patients to reduce the risk of heart attack, stroke, chest pain caused by angina, or blood vessel blockage. It is also used in certain patients to reduce the risk of hospitalization for congestive heart failure, or the need for medical procedures to open blocked heart blood vessels. It may also be used for other conditions as determined by your doctor.

Atorvastatin is an HMG-CoA reductase inhibitor, also known as a "statin." It works by reducing the production of certain fatty substances in the body, including cholesterol...