High Cholesterol: What It Means, Causes, and Why It's Dangerous

You opened a lab report, saw a number marked above normal — and now you want to understand what it means. Cholesterol is a waxy, fat-like substance found in every cell of the body: it is used to build hormones, vitamin D, and substances that help digest food. Below — the numbers, causes, and risks to blood vessels.

What hypercholesterolemia is

Hypercholesterolemia is an elevated level of cholesterol in the blood. The body produces all the cholesterol it needs on its own, and some is added by animal products: egg yolks, meat, cheese. In the blood, lipids don't float on their own — they attach to proteins and become lipoproteins. HDL, the "good" cholesterol, collects excess from tissues and carries it to the liver, which removes cholesterol from the body. LDL, the "bad" one, at high levels leads to plaque buildup in the arteries. VLDL mainly transports triglycerides.

Reference points at which dyslipidemia is diagnosed: total cholesterol above 5.0 mmol/L, LDL above 3.0 mmol/L, HDL below 1.0 mmol/L in men and below 1.2 mmol/L in women, triglycerides above 1.7 mmol/L.

How to tell that cholesterol is elevated: blood test

High cholesterol usually has no symptoms — the level can only be found through a blood test. Myth: the body gives a signal on its own when cholesterol goes out of range. Fact: elevated blood cholesterol usually causes no symptoms, and its level can only be determined by a blood test.

How often to get checked depends on age, risk factors, and family history. Before age 19, the first test is done at 9–11 years, then every 5 years; some children start testing at age 2 if there was high cholesterol, heart attack, or stroke in the family. At 20–65, young adults need a test once every 5 years; men 45–65 and women 55–65 — once every 1–2 years. After 65 — annually.

Why cholesterol rises: main causes

The most common cause is lifestyle. Specifically:

• a diet with excess saturated fats — red meat, fatty dairy products, chocolate, some baked goods, deep-fried food, and processed foods;
• little movement and lots of sitting — this lowers "good" HDL;
• smoking — hits HDL especially hard in women and raises LDL;
• excess alcohol — raises total cholesterol;
• stress — through hormones such as corticosteroids, the body produces more cholesterol.

Next is heredity: familial hypercholesterolemia produces very high numbers from a young age. Risk is higher in people over 50, in men, in women after menopause, and in people of South Asian and sub-Saharan African origin. Levels are raised by diabetes, chronic kidney disease, HIV, lupus, excess weight, and some medications: steroids, certain chemotherapy drugs, agents used after organ transplantation, drugs for some heart diseases, and some acne treatments.

High cholesterol in women: specifics

At 20–39, men are at greater risk than women. Then the picture changes: after menopause, risk in women rises because the level of female hormones that protected the vessels falls. Smoking lowers "good" HDL more strongly in women. And the threshold for women is stricter: HDL below 1.2 mmol/L is already abnormal, whereas in men the cutoff is 1.0 mmol/L.

Why high cholesterol is dangerous

Excess cholesterol combines with other substances and forms a plaque that sticks to the artery wall. This is atherosclerosis. Next comes narrowing of the lumen and coronary heart disease. The plaque can rupture, a clot forms on its surface, and blood flow through the coronary artery is partially or completely blocked: this is how anginal chest pain and heart attack occur. Plaques also grow in other vessels, including those carrying blood to the brain and limbs — hence carotid artery disease, stroke, and peripheral arterial disease. Certain forms of hyperlipidemia are associated with acute pancreatitis.

When to see a doctor

The reason is the test result itself with elevated cholesterol, even when you feel fine. The doctor assesses the numbers together with age, weight, smoking, diabetes, and family history, and decides how often to repeat the lipid profile. Familial hypercholesterolemia is an inherited condition with very high cholesterol levels.

High cholesterol by itself is not a reason to call an ambulance. 103/112 — if chest pain or signs of stroke appear: these are life-threatening conditions.

This material is for reference: the number on the report is a reason to talk to a doctor, not to make decisions on your own.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer