High Cholesterol: Causes, Symptoms, Diagnosis, and Treatment

High cholesterol, or hyperlipidemia, occurs when there is an excess of lipids or fats in the blood. This condition can increase the risk of heart attack and stroke because it may lead to the buildup of plaque in the blood vessels, particularly the arteries.

Cholesterol is a waxy substance the body requires to build healthy cells and support various functions, such as the production of hormones. The liver produces cholesterol to aid in digestion and hormone creation, but cholesterol is also consumed through dairy and meat products.

Understanding LDL and HDL Cholesterol

There are two primary types of cholesterol: low-density lipoprotein (LDL), often called bad cholesterol, and high-density lipoprotein (HDL), known as good cholesterol.

Elevated levels of LDL or insufficient levels of HDL can cause plaque to accumulate in the arteries. Without medical management, this buildup can lead to cardiovascular disease.

Causes and Risk Factors

Lifestyle habits are among the most common causes of high cholesterol. These include a diet high in saturated fat, a lack of regular physical activity, smoking, and excessive alcohol intake.

Certain medical conditions can also increase the risk of high cholesterol, including:

• Type 2 diabetes
• Chronic kidney disease
• Hypothyroidism
• Overweight and obesity

Some medications used to treat other health issues may raise LDL levels or lower HDL levels. These include corticosteroids like prednisone, retinoids used for acne or psoriasis, certain arrhythmia medications such as amiodarone, and some diuretics or beta-blockers used for high blood pressure.

Other medications that may impact cholesterol levels include immunosuppressive drugs like cyclosporine, certain chemotherapy medications, and HIV drugs such as protease inhibitors.

Non-controllable factors also play a role. Family history is a significant risk factor, and some individuals have an inherited genetic condition called familial hypercholesterolemia (FH) that causes very high LDL cholesterol at a young age.

Age and sex also influence risk. As people age, the body may become less efficient at clearing cholesterol from the blood. Generally, women tend to have lower LDL cholesterol than men until menopause, while men typically have lower HDL cholesterol than women regardless of age.

Diagnosis and Symptoms

High cholesterol typically does not cause any symptoms. A blood test is the only way to determine if cholesterol levels are elevated.

To diagnose the condition, doctors may perform a physical exam and review a patient’s eating habits, activity levels, and family history. They may order a lipid profile, or lipid panel, which measures LDL, HDL, and triglycerides.

Patients may be required to fast for 8 to 12 hours before the blood draw. Normal HDL levels are generally considered to be 50 to 80 mg/dL for women and 40 to 80 mg/dL for men.

Complications and Long-term Risks

If left untreated, high cholesterol can lead to atherosclerosis, where plaque builds up in the arteries. This can result in several cardiovascular problems, including:

• Coronary artery disease
• Heart attack
• Stroke
• Carotid artery disease
• Peripheral artery disease

Treatment and Management

Managing cholesterol is a long-term effort involving lifestyle changes and, in some cases, medication.

Lifestyle recommendations include eating a heart-healthy diet by increasing fiber and focusing on lean proteins and plant-based foods while reducing saturated and trans fats. Engaging in 150 minutes of moderate-intensity physical activity per week can help clear cholesterol from the blood.

Other preventative measures include maintaining a healthy weight, quitting smoking, limiting alcohol intake, and ensuring adequate sleep, as poor sleep is linked to higher LDL and triglycerides.

Medical treatments include various drug classes:

• Statins: These inhibit cholesterol production in the liver and remove LDL from the bloodstream. Examples include atorvastatin, rosuvastatin, and simvastatin.
• Cholesterol absorption inhibitors: Such as ezetimibe, which lowers the amount of cholesterol absorbed from food.
• PCSK9 inhibitors: Such as alirocumab, evolocumab, and inclisiran, which help the liver absorb more LDL.
• Bempedoic acid: An alternative for those who experience serious side effects from statins.
• Bile acid sequestrants: Such as cholestyramine and colesevelam, which prompt the liver to use extra cholesterol to make bile acids.
• Fibrates: Such as fenofibrate and gemfibrozil, which increase HDL and speed the removal of triglycerides.
• Omega-3 fatty acids: High doses can lower triglyceride levels.

Screening Guidelines

Regular screenings are essential for managing cholesterol. While healthy adults generally check every four to six years, specific guidelines suggest:

• People under age 45: Every 5 years.
• Men ages 45 to 65 and women ages 55 to 65: Every 1 to 2 years.
• People over age 65: Every year.

For children, diet and exercise are typically the first treatments for those age 2 and older. Children age 10 and older with very high levels may be prescribed statins.