Cholesterol
Cholesterol is a waxy, fat‑like substance essential for hormone and vitamin D production, but excess levels can form arterial plaque and increase the risk of heart disease.
What is cholesterol?
Cholesterol is a waxy, fat‑like substance found in every cell of the body. The body needs it to make hormones, vitamin D, and substances that aid digestion. All cholesterol is produced internally, though it is also present in animal‑based foods such as egg yolks, meat, and cheese.
plaque. Plaque adheres to arterial walls, a process known as atherosclerosis, which can narrow or block coronary arteries and lead to coronary artery disease.
HDL, LDL, and VLDL
HDL, LDL, and VLDL are types of lipoproteins, complexes of fat (lipid) and protein that transport lipids through the bloodstream. Each has a distinct role:
- HDL (high‑density lipoprotein) is often called “good” cholesterol because it carries cholesterol from peripheral tissues back to the liver for removal.
- LDL (low‑density lipoprotein) is labeled “bad” cholesterol; high LDL levels promote plaque buildup in arteries.
- VLDL (very low‑density lipoprotein) also contributes to plaque formation, primarily by transporting triglycerides, whereas LDL mainly carries cholesterol.
Causes of high cholesterol
The most common cause is an unhealthy lifestyle, which may include:
- Unhealthy eating habits – excess saturated fats from red meat, full‑fat dairy, chocolate, baked goods, and deep‑fried or processed foods can raise LDL cholesterol.
- Lack of physical activity – prolonged sitting and little exercise lower HDL cholesterol.
- Smoking – reduces HDL (especially in women) and raises LDL.
- Stress – may increase cortisol and other hormones that stimulate cholesterol production.
- Excessive alcohol consumption – can raise total cholesterol.
Genetic factors also play a role; for example, familial hypercholesterolemia (FH) is an inherited condition that causes very high blood cholesterol. Certain medical conditions and medications can similarly raise LDL or lower HDL.
Risk factors for high cholesterol
A variety of factors can increase the likelihood of elevated cholesterol:
- Age – levels tend to rise with age, though children and teens can also be affected.
- Sex – men aged 20‑39 have higher risk than women; after menopause, women’s risk increases.
- Family history – cholesterol levels often run in families.
- Other health conditions – diabetes, chronic kidney disease, HIV, and lupus elevate risk.
- Medications – steroids, some chemotherapy agents, post‑transplant drugs, certain heart medicines, and specific acne treatments can raise LDL or lower HDL.
- Race or ethnicity – Asian Americans are more likely to have high LDL, while non‑Hispanic Whites often have higher total cholesterol.
- Weight – overweight or obesity contributes to higher cholesterol levels.
Health problems linked to high cholesterol
When left untreated, high cholesterol can cause serious complications:
- Large plaque deposits may rupture, forming a blood clot that can block a coronary artery.
- Reduced or blocked blood flow to the heart can cause angina (chest pain) or a heart attack.
- Plaque buildup in other arteries can lead to carotid artery disease, stroke, and peripheral arterial disease.
Diagnosis
High cholesterol typically produces no symptoms. A blood test measures cholesterol levels, with testing frequency based on age, risk factors, and family history.
People age 19 or younger:
- First test between ages 9‑11.
- Repeat every 5 years.
- Earlier testing (as young as age 2) may be advised if there is a strong family history of high cholesterol, heart attack, or stroke.
People age 20‑65:
- Generally every 5 years.
- Men 45‑65 and women 55‑65 should test every 1‑2 years.
People over age 65:
- Annual testing is recommended.
Treatment & Management
Heart‑healthy lifestyle changes are the first line of defense and include:
- A heart‑healthy eating plan.
- Weight management.
- Regular physical activity.
If lifestyle modifications are insufficient, medications such as statins may be prescribed. Even when taking medication, continuing healthy habits remains essential.
Individuals with familial hypercholesterolemia may undergo lipoprotein apheresis, a procedure that filters LDL cholesterol from the blood and returns the remaining blood to the patient.