How to Read Your Cholesterol Results the Right Way

Cholesterol is a waxy substance your body needs to build cells and hormones. It travels through your blood inside carriers called lipoproteins, and those carriers are what a cholesterol test actually measures. That is why the panel has several lines rather than one. Here is what each one is.

• Total cholesterol is roughly the sum of the carriers. On its own it is the least useful number, because it does not tell you the balance between the good and bad carriers.
• LDL (low-density lipoprotein) is often called the bad cholesterol. It is the carrier that can deposit cholesterol in artery walls, so a higher LDL generally means higher heart risk.
• HDL (high-density lipoprotein) is often called the good cholesterol. It helps carry cholesterol away from your arteries and back to your liver, so here a higher number is protective.
• Triglycerides are a different type of fat carried in your blood. They rise with excess calories, sugar and alcohol, and high levels add to cardiovascular risk.

Cholesterol is reported in one of two units depending on where you live: millimoles per litre (mmol/L), common in the UK and much of the world, or milligrams per decilitre (mg/dL), common in the United States. The table shows widely used general reference points for a healthy adult. Your own targets, especially for LDL, depend heavily on your overall heart risk, so read these as orientation only.

Here is the trap. Because total cholesterol lumps LDL and HDL together, two people can have the exact same total and completely different risk. Imagine two people both with a total of 5.5 mmol/L. One has high LDL and low HDL, which is a poor picture. The other has moderate LDL and very high, protective HDL, which is a good picture. Same headline number, opposite meaning.

This is why doctors often look at the total-to-HDL ratio, which divides your total by your HDL. A lower ratio is better. It captures the balance the single total number hides. So if your total looks slightly high but your HDL is excellent, do not panic before you have seen the breakdown. And if your total looks fine but your HDL is very low and LDL high, the reassuring total is masking a problem.

Triglycerides deserve their own note because they behave differently from cholesterol. They are the form your body stores spare energy in, and they respond quickly to what you have been eating and drinking. A run of high-sugar meals, heavy alcohol, or simply eating more calories than you burn will push them up, sometimes within days.

That responsiveness cuts both ways, which is the encouraging part. Of all the numbers on the panel, triglycerides often move the fastest when you change your habits. Cutting back on sugary drinks and alcohol, losing some excess weight, and adding regular activity can bring them down noticeably in a matter of weeks.

If your results are not where you want them, plenty is within your control, though the levers differ for each number. None of this replaces the plan your doctor makes with you, and some people need medication regardless of lifestyle because of their genetics or overall risk.

1. Move regularly. Aerobic exercise like brisk walking or cycling is one of the few things that reliably raises protective HDL and lowers triglycerides. Aim for around 150 minutes a week of moderate activity.
2. Change the fats, not just the amount. Swapping saturated fats for unsaturated ones, more fish, nuts, olive oil and less processed and fatty meat, tends to lower LDL.
3. Add soluble fibre. Oats, beans, lentils and fruit contain fibre that helps carry cholesterol out of the body, nudging LDL down.
4. Cut excess sugar and alcohol. These are the biggest drivers of high triglycerides. Reducing sugary drinks and heavy drinking often moves that number fastest.
5. Lose excess weight if relevant. Even modest weight loss can improve LDL, HDL and triglycerides together.