Hyperlipidemia (high cholesterol)

Cholesterol is a fatty substance your body needs, carried around in the blood by particles. Hyperlipidemia, usually called high cholesterol, means there is too much of the harmful kind of cholesterol, or too much of a related fat called triglycerides. It causes no symptoms of its own, so most people find out from a blood test rather than from anything they feel.

What high cholesterol is, and what it is not

Cholesterol is not simply something you eat. Your body makes it, and how much ends up in your blood depends on genetics as well as on food, activity, alcohol and other conditions. LDL, sometimes called the harmful kind, can leave deposits in artery walls, while HDL carries cholesterol away. Over years those deposits narrow the arteries in the heart, the brain and the legs, which is what makes the numbers worth watching.

It is also not only a condition of later life or of larger bodies. Familial hypercholesterolemia is an inherited condition that raises LDL from birth, and people who look and feel healthy can carry it. Measured Canadian survey results show how common untreated high cholesterol is: among adults with unhealthy cholesterol levels, 27% had never been diagnosed, and a further 28% had been diagnosed but were not at target.

Signs and symptoms

• Usually no symptoms at all, which is why it is found through a blood test
• In some inherited forms, fatty yellowish lumps in the skin or tendons, often on the knuckles, elbows or heels
• A pale ring around the coloured part of the eye, especially before age 45
• Small yellow patches on the eyelids
• Chest discomfort with activity, which is a sign of narrowed arteries rather than of the cholesterol itself
• Leg pain or cramping when walking that eases with rest
• Abdominal pain from irritation of the pancreas, when triglycerides are very high

Because there is usually nothing to feel, the picture differs less between people than the numbers do, and the only way to know where you stand is a blood test.

What raises the risk

Some risk factors cannot be changed:

• Getting older, and menopause in women
• Family history, including familial hypercholesterolemia, an inherited condition that raises LDL from birth
• Chronic kidney disease and an underactive thyroid
• Some medicines taken for other conditions

Others can often be worked on, usually with support from a health care team:

• Eating patterns high in saturated and trans fats, refined sugars and alcohol
• Low physical activity, and living with obesity, especially weight carried around the waist
• Smoking
• Diabetes, and blood sugar that stays high

How high cholesterol is diagnosed in Canada

High cholesterol is found with a blood test called a lipid panel, which reports total cholesterol, LDL, HDL, non-HDL cholesterol and triglycerides. Canadian practice no longer requires fasting for most people. A family doctor or nurse practitioner usually orders it alongside blood sugar, kidney and thyroid tests, then combines the result with your age, blood pressure, smoking status and family history to estimate overall cardiovascular risk. Current Canadian lipid guidance also supports measuring lipoprotein(a) once in adult life, and people with very high LDL or a strong family history may be assessed for familial hypercholesterolemia and referred to a lipid clinic.

Treatment and day-to-day management

Clinical research for Hyperlipidemia (high cholesterol) is enrolling. See the current studies ↓

Care is aimed at the overall risk to your arteries, not at the cholesterol number in isolation, so two people with similar results may be offered different plans. Depending on your risk and your history, a health care team may discuss:

• Statins, the most widely prescribed lipid lowering class in Canada
• Ezetimibe and bile acid sequestrants
• PCSK9 targeted therapies, including injectable antibodies and the small interfering RNA agent inclisiran
• Fibrates and prescription omega-3 preparations, used mainly when triglycerides are high
• Dietary counselling, physical activity programs, stop-smoking support, and referral to a lipid clinic for inherited forms, with lipoprotein apheresis reserved for rare severe cases

Whether medicine is added, and which one, depends on your own numbers and your overall risk. That is a decision for you and your own clinician, and nothing on this page is a recommendation about any of these options.

When to talk to a doctor

• Call 911 for chest pain or pressure lasting more than a few minutes, or for sudden weakness, face drooping or trouble speaking. High cholesterol itself causes no emergency, but the artery disease behind it can.
• See your doctor promptly if you develop severe upper abdominal pain, which can happen when triglycerides are very high.
• Book an appointment if a parent, brother or sister had a heart attack or stroke before age 55 in men or 65 in women, or if you notice fatty lumps in the skin or tendons, since these can point to an inherited form.

Why clinical research matters for high cholesterol

Even people already taking statins can be left with cholesterol above target, or can still have a heart attack or stroke, and two blood fats in particular, lipoprotein(a) and triglyceride rich remnants, have no widely available treatment aimed at them. Studies now recruiting include oral PCSK9 inhibitors, antisense and small interfering RNA agents targeting lipoprotein(a), ANGPTL3 and apolipoprotein C-III, CETP inhibitors, and gene editing approaches for familial hypercholesterolemia. Researchers are also studying how to find families affected by familial hypercholesterolemia earlier through cascade screening of relatives.

Those approaches only become options through clinical studies. Taking part is voluntary, you give informed consent before anything starts, and you can withdraw at any time without affecting the care you get from your own doctor. No one can say in advance whether a study will help you personally.

Learn more from Canadian sources

• Heart & Stroke
• Public Health Agency of Canada: high cholesterol
• Canadian Cardiovascular Society dyslipidemia guidelines
• Hypertension Canada