Cholesterol is a waxy, fat-like substance, or lipid, made both naturally by the body and deposited through certain foods. The liver makes cholesterol that it needs to form cells, make hormones, and vitamin D. Cholesterol is made of different lipids that do not dissolve in the blood. Too much cholesterol in your blood is harmful to the body.
Types of cholesterol
The cholesterol travels through the blood on two commonly known lipoproteins:
- Low-density lipoproteins (LDLs), known as “bad” cholesterol, build up and block arteries. For adults, the preferred level for LDL is below 100 mg/dL* (milligrams per deciliter).
- High-density lipoproteins (HDLs) are known as “good cholesterol.” HDL helps carry other cholesterol away to be removed from the body by the liver. The preferred level for adults is greater than 60 mg/dL*.
*Numbers may vary depending on health care practice regulations.
What causes high cholesterol?
High cholesterol levels are known as hypercholesterolemia or hyperlipidemia. There are several causes of high cholesterol, which can sometimes be a combination. High cholesterol can be:
- Family history of high cholesterol
- Due to a poor diet high in saturated fat, trans fats, or processed foods
- From poor exercise habits
- Related to being overweight or obese
- Certain medications may raise cholesterol: beta-blockers, diuretics, immunosuppressives, retinoids, steroids, chemotherapy, etc.
Who’s at risk?
There are several risk factors for elevated cholesterol. Some can be changed while others cannot. It is important to be aware of those that can be changed and work toward correcting them. In addition to the causes listed above, risk factors also include:
- High blood pressure
- Alcohol use (more than 1 to 2 drinks per day increases the risk)
- Family history of heart disease
- Age: Cholesterol levels rise with age, though it is important to note that even children can have elevated cholesterol, especially at puberty
- Gender: Men tend to have higher cholesterol; however, women's levels increase after menopause
- Ethnicity: Caucasians are more likely to have high total cholesterol
- Other medical conditions: Chronic kidney disease, HIV, hypothyroidism, polycystic ovary syndrome, sleep apnea
What happens when cholesterol is high?
When cholesterol levels are high, the waxy substance builds up on artery walls and can create plaque. This leads to narrowing and clogging of the arteries. The arteries can become hard and not function properly, known as atherosclerosis.
If the arteries become narrow, they have a harder time moving blood throughout the body. This can result in shortness of breath with movement or chest pain. When plaque builds up in the artery, it also increases the risk of clots. Clots can break free from the plaque and block arteries, causing stroke or heart attack.
Diagnosing elevated cholesterol
Your healthcare provider can diagnose high cholesterol based on family history, a physical exam, and blood tests. During the exam, your provider will ask about your diet, exercise, medications, and family history of cholesterol, stroke, heart attack, or heart or blood vessel disease.
Your provider will order a blood test called a lipid panel. A lipid panel (also known as lipid profile or lipoprotein panel) measures LDL and HDL levels as well as total cholesterol and triglycerides.
- Total cholesterol is the combined amount of all cholesterol of LDL and HDL in the blood.
- Triglycerides are another type of fat that converts from food. When too much is taken in, the extra ends up in the blood rather than fat cells. This can be a problem with people with waist measurements greater than 40 inches in men and 35 inches in women.
This test generally requires fasting, or nothing to eat or drink, for 9 to 12 hours. Eating or drinking things other than water can interfere with testing causing false high results. However, some patients cannot fast, which will be determined by the healthcare provider.
Treating and management
Healthy diet. Whether you have a family history of high cholesterol or not, you can decrease your risk of increased cholesterol by following a heart healthy diet. Avoid saturated fats, trans fats, and foods high in cholesterol. Saturated fats are in products that come from animals – meat, milk, butter, cheese, etc. Trans fats are in oil, processed, fast, and fried foods. Several diets can help lower your cholesterol levels. Discuss this with your provider to see which is best for you.
Exercise. Thirty minutes of exercise can help lower your LDL and raise your HDL. Moderate exercise most days of the week can be beneficial. Talk to your healthcare provider to ensure the activities you pick are safe.
Weight loss. Losing inches if your abdomen exceeds 40 inches in men and 35 inches in women can help decrease your cholesterol and triglycerides. It also lowers your risk of heart disease and other health problems.
Medications are available if diet, exercise, and weight loss do not help.
- Statins are the most commonly used drug for lowering LDLs by decreasing the body’s production and increasing the removal of LDLs. Some people develop muscle aches and cannot take them. These include atorvastatin, lovastatin, pravastatin, and more.
- Bile acid sequestrants, like Cholestyramine, stick to bile, preventing it from being used for digestion. The liver uses more cholesterol to make more bile.
- Fibrates decrease triglycerides and possibly increase HDLs. Fenofibrate and gemibrozil.
- Other treatments include Omega 3 fatty acids and niacin.
Preventing high cholesterol
Screening should begin around age nine to eleven and be repeated every five years. Some children are screened at age two if they have a family history of high cholesterol, heart attack, or stroke. Recommendations are for people between the ages 20 to 65 to have their cholesterol levels checked every year to ensure levels are in an acceptable range. Monitoring should be done yearly for those over age 65. This helps their provider monitor elevation and lower their risk.
Johns Hopkins Medicine. Cholesterol in the Blood
Cleveland Clinic. Cholesterol Numbers: What Do They Mean
National Library of Medicine. Lee, Y. & Siddiqui, W. Cholesterol levels
Icahn School of Medicine at Mount Sinai. Hypercholesterolemia
National Heart, Lung, and Blood Institute. Blood Cholesterol