Benjamin Wedro, MD, FACEP, FAAEM
Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
William C. Shiel Jr., MD, FACP, FACR
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In this Article
- Cholesterol levels facts
- What is cholesterol?
- What are LDL and HDL cholesterol?
- What determines the level of LDL cholesterol in the blood?
- Does lowering LDL cholesterol prevent heart attacks and strokes?
- How can LDL cholesterol levels be lowered?
- What are "normal" cholesterol blood levels?
- What are the 2013 ACC/AHA Guidelines?
- Why is HDL the good cholesterol?
- What are LDL/HDL and total/HDL ratios?
- How can levels of HDL cholesterol be increased?
- What are triglycerides and VLDL?
- Do high triglyceride levels cause atherosclerosis?
- What causes elevated triglyceride levels?
- How can elevated blood triglyceride levels be treated?
- What medications are available to lower cholesterol, lipids, and triglycerides?
- Is lowering LDL cholesterol enough?
Why is HDL the good cholesterol?
HDL is the good cholesterol because it protects the arteries from the atherosclerosis process. HDL cholesterol extracts cholesterol particles from the artery walls and transports them to the liver to be disposed of in the bile. It also interferes with the accumulation of LDL cholesterol particles in the artery walls.
The risk of atherosclerosis and heart attacks is strongly related to HDL cholesterol levels. Low levels of HDL cholesterol are linked to a higher risk, whereas high HDL cholesterol levels are associated with a lower risk.
Very low and very high HDL cholesterol levels can run in families. Families with low HDL cholesterol levels have a higher incidence of heart attacks than the general population, while families with high HDL cholesterol levels tend to live longer with a lower frequency of heart attacks.
Like LDL cholesterol, lifestyle factors, and other conditions influence HDL cholesterol levels. HDL cholesterol levels tend to be lower in persons who smoke cigarettes or have type 2 diabetes and in those who are overweight or inactive.
HDL cholesterol is higher in people who are lean, exercise regularly, and do not smoke cigarettes. Estrogen increases a person's HDL cholesterol, which explains why women generally have higher HDL levels than men do.
For individuals with low HDL cholesterol levels, a high total or LDL cholesterol blood level further increases the incidence of atherosclerosis and heart attacks. Therefore, the combination of high levels of total and LDL cholesterol with low levels of HDL cholesterol is undesirable whereas the combination of low levels of total and LDL cholesterol and high levels of HDL cholesterol is favorable.
What are LDL/HDL and total/HDL ratios?
The total cholesterol to HDL cholesterol ratio (total chol/HDL) is a number that is helpful in estimating the risk of developing atherosclerosis. The number is obtained by dividing total cholesterol by HDL cholesterol. (High ratios indicate a higher risk of heart attacks, whereas low ratios indicate a lower risk).
High total cholesterol and low HDL cholesterol increases the ratio and is undesirable. Conversely, high HDL cholesterol and low total cholesterol lowers the ratio and is desirable. An average ratio would be about 4.5. Ideally, one should strive for ratios of 2 or 3 (less than 4).
Tips to keep it under control.