Types

• LDL stands for low density lipoprotein while HDL stands for high density lipoprotein; LDL is called bad cholesterol because it can build up along the sides of arteries and clog them as it flows through blood. HDL--the "good" cholesterol--helps to keep the circulatory system clean and healthy.
  
  

Sources

• Foods derived from animals are high in saturated fat and tend to be high in LDL, like fatty red meats, organ meats, and egg yolks. Eating foods like nuts and fish can help boost HDL.
  
  

Cholesterol Levels

• The total level of LDL in the blood is an important measure of risk for cardiovascular disease. According to the Mayo Clinic, an average person should aim for an LDL level less than 130 milligrams per deciliter of blood. The American Heart Association states that HDL levels below 40 mg/dL are associated with greater risk of heart disease.
  
  

Health Impact

• High levels of LDL and low levels of HDL are strongly associated with an increased likelihood of heart attack, stroke, and other severe circulatory complications.
  
  

Prevention

• Eating foods high in soluble fiber and avoiding animal based foods can lower the risk of high cholesterol, since plant foods contain no cholesterol. Medications like Lipitor can also help lower cholesterol.