Cholesterol has a bad reputation but the truth is far more nuanced. Your body needs cholesterol to build cells, make hormones, and digest food. The key is understanding which kind of cholesterol you have, in what proportion, and what that means for your heart.
What Is Cholesterol, Really?
Cholesterol is a waxy, fat-like substance produced by your liver and also absorbed from certain foods. Because it cannot dissolve in blood, it is carried through your bloodstream by proteins called lipoproteins. The two most important are Low-Density Lipoprotein (LDL) and High-Density Lipoprotein (HDL) and understanding the difference between them is the single most important thing you can do to assess your cardiovascular risk.
A standard lipid profile blood test measures four things: total cholesterol, LDL, HDL, and triglycerides. But a raw number tells only part of the story. What matters most is the ratio and balance between these components.
LDL: The One to Watch
LDL is often called "bad" cholesterol though that framing is an oversimplification. LDL carries cholesterol to cells throughout the body, which is necessary and useful. The problem arises when LDL levels are too high.
Excess LDL accumulates in the walls of arteries, triggering inflammation and the buildup of plaques. Over years and decades, these plaques narrow the arteries a process called atherosclerosis. When a plaque ruptures, a blood clot forms and can completely block an artery, causing a heart attack or stroke.
LDL Target Levels
For most healthy adults: below 100 mg/dL. For those with diabetes or existing heart disease: below 70 mg/dL. For very high-risk patients after a heart attack: below 55 mg/dL is the current European and Indian guideline target.
The type of LDL particles also matters. Small, dense LDL particles are particularly dangerous as they penetrate arterial walls more easily than larger, fluffy LDL particles though most standard tests don't distinguish between these.
HDL: The Cleaner
HDL is the "good" cholesterol and it earns that label. HDL acts as a reverse cholesterol transporter: it picks up excess cholesterol from artery walls and tissues and carries it back to the liver, where it is broken down and eliminated. Think of it as the body's built-in arterial cleaner.
Higher HDL levels are strongly protective against heart disease. Low HDL below 40 mg/dL in men or below 50 mg/dL in women is an independent risk factor for cardiovascular events, even if your total cholesterol appears normal.
Factors that raise HDL include regular aerobic exercise, quitting smoking, moderate alcohol consumption (though alcohol carries its own risks), and a diet rich in healthy fats such as olive oil, nuts, and fatty fish.
Triglycerides: The Third Factor
Often overlooked in the cholesterol conversation, triglycerides are the most common type of fat in the body. Elevated triglycerides particularly above 200 mg/dL significantly amplify cardiovascular risk, especially when combined with low HDL and high LDL. This combination is sometimes called atherogenic dyslipidaemia and is particularly common in South Asians.
High triglycerides are strongly linked to dietary habits: excess refined carbohydrates, sugar, alcohol, and sedentary behaviour are the primary drivers. They respond well to lifestyle changes, often more dramatically than LDL does.
What You Should Do
Get a fasting lipid profile at least once every five years from the age of 35 or earlier if you have diabetes, hypertension, obesity, or a family history of heart disease. Know your numbers. Ask your doctor not just about your total cholesterol, but your LDL, HDL, triglycerides, and the LDL-to-HDL ratio.
If your numbers are out of range, the first line of treatment is always lifestyle: a Mediterranean-style diet, regular exercise, weight management, quitting smoking, and limiting sugar and refined carbohydrates. Statins and other medications are highly effective when lifestyle changes alone are insufficient and they save lives. There is no reason to avoid them if your cardiologist recommends them.
Dr. Priya Nair
Dr. Priya Nair is a cardiologist and echocardiographer at MNR Hospital with 14 years of clinical experience. Trained at KMC Manipal, she specialises in non-invasive cardiac diagnosis, echocardiography, and preventive heart care for women.
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