(HealthDay News) -- There are two types of cholesterol: high-density lipoproteins (HDL) and low-density lipoproteins (LDL). When you get your cholesterol levels checked, your doctor will usually give you both readings.
LDL cholesterol is often called "bad" cholesterol because high levels are linked to an increased risk of heart disease, heart attack and stroke, says the American Heart Association (AHA). This cholesterol, together with other substances, builds up and forms plaque inside artery walls, causing blockages that can limit blood flow. LDL of less than 100 mg/dL is optimal, the ADA says.
HDL cholesterol often is called "good" cholesterol, because sufficient levels have been found to reduce a person's risk of heart attack. Experts think it may carry "bad" cholesterol away from the arteries to the liver, where the LDL can be passed from the body, the AHA says. HDL cholesterol levels of less than 40 mg/dL increase a person's risk of heart disease, the AHA says.