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Total Cholesterol

Often associated with negative health outcomes, cholesterol has several important functions within the body, but it can also be a good heart health indicator.

Author: Leanne Edermaniger

April 19, 2024

Reviewed by: Dr Thom Phillips

In this article:

What is Total Cholesterol?

Cholesterol is a waxy, yellow type of fat, also known as a lipid. You’ll likely be familiar with dietary cholesterol, the type found in foods, like eggs, red meat and shellfish, but the human body makes most of its cholesterol.

Cholesterol is mostly made in the liver, where it then enters the bloodstream, travelling within the circulatory system carried by lipoproteins. There are seven classes of lipoproteins in total, but the two most commonly known are low-density lipoprotein (LDL) and high-density lipoprotein (HDL)[1].

LDL is widely considered to be “bad” and HDL is commonly referred to as “good” cholesterol. Simply because LDL transports cholesterol from the liver to the rest of the cells in the body and HDL takes cholesterol back to the liver for processing[2].

Every cell contains cholesterol, and it has many significant roles, like maintaining the structure of cell membranes, providing the building blocks for some hormones, and making bile to help you digest fats.

When you test your cholesterol levels, your results will show you:

  • Total cholesterol: That’s the whole amount of cholesterol in your blood, both good and bad.
  • HDL (high-density lipoprotein): The good cholesterol that transports excess cholesterol from your arteries to your liver.
  • LDL (low-density lipoprotein): The bad cholesterol that deposits excess cholesterol on the artery rules, increasing the risk of heart disease.
  • HDL ratio: The percentage of good cholesterol in your blood.
  • Triglycerides: The main type of fat present in the body, high levels increase the risk of heart disease.

How is Total Cholesterol Calculated?

A blood sample is required to calculate total cholesterol levels.

The formula used to calculate total cholesterol, the total amount of cholesterol, good and bad, circulating in your blood, is:

Total cholesterol = HDL + LDL + 20% triglycerides

What is a Good Total Cholesterol Level?

Cholesterol levels can be a good cardiovascular risk indicator, with lower levels usually representing a lower risk.

The ideal total cholesterol level should be below 5.0 mmol/L[3].

Keeping your total cholesterol below 5 nmol/L can help prevent cardiovascular disease (CVD).

The British Heart Foundation recommends:

  • Total cholesterol should usually be 5mmol/L or below
  • HDL (good cholesterol) should usually be 1mmol/L or above
  • Non-HDL (bad cholesterol) should usually be 4mmol/L or below
  • Total cholesterol to HDL ratio should usually be 6 or below

Our data shows that the average total cholesterol level for Forth customers is 5.25 mmol/L – 5.21 mmol/L for men and 5.29 mmol/L for women – which is below the UK average.

Although women tend to have higher total cholesterol levels than men, more than half of men (53%) and women (56%) have high total cholesterol levels in our dataset.

Why is Checking Total Cholesterol Important?

Because cholesterol is a fatty substance that travels around in your blood, if your levels are high you may be at a greater risk of heart disease or other cardiovascular-related issues.

A total cholesterol test will give you an insight into your levels of HDL and LDL cholesterol, and another type of fat called triglycerides.

Although your levels of each type of cholesterol will vary, generally, the lower your LDL levels are, the better. As part of a cholesterol test, you’ll also be given your HDL ratio which will show you how much HDL is in your blood compared to total cholesterol.

These figures can help determine if lifestyle changes, such as diet, could be beneficial.

A cholesterol test can initiate lifestyle changes

You’re unlikely to know if you have high cholesterol because it often doesn’t have any symptoms. That’s why it is sometimes known as a ‘silent killer’.

By proactively checking your cholesterol levels, you’ll have a better understanding of your heart attack or stroke risk.

If your levels are high, the test may be enough to kickstart some lifestyle changes that can help lower your cholesterol levels, such as dietary improvements and increased exercise.

Screen for underlying health problems

A cholesterol test can provide a starting point for screening for health problems, including:

  • Atherosclerosis
  • Heart disease

A doctor can use your cholesterol levels along with other parameters to estimate your cardiovascular disease risk. They may also give you a QRISK score. That is an estimate of how likely you are to develop heart or circulatory problems in the next decade[4].

What Causes High Cholesterol Levels

Several things can contribute to high cholesterol levels, including:

  • Diet: Not following a healthy, balanced diet can raise your LDL cholesterol levels. For example, eating foods rich in saturated fats, such as fatty cuts of meat and dairy products, and following a typical Western diet are contributing factors[5].
  • Little or no exercise: Research shows that a lack of exercise can result in a 7% rise in total cholesterol and a 16% increase in LDL levels[6].
  • Genetics: In the UK, approximately 260,000 people have a genetic predisposition towards high cholesterol levels, a condition called familial hypercholesterolaemia[7].
  • Smoking: Smoking has a two-fold effect on cholesterol because it increases the ‘stickiness’ of LDL cholesterol, making it easier to attach to artery walls, and it lowers your HDL levels which usually take cholesterol away[8].
  • Menopause: Postmenopausal women have significantly higher total cholesterol, LDL and triglyceride levels compared to premenopausal women[9]. A study involving Korean women found that postmenopausal women have higher total cholesterol and HbA1c levels compared to premenopausal women[10].
  • Age: From 20 to 65 years, total cholesterol levels gradually rise, after which they seem to plateau in women and may lower slightly in men. However, it isn’t uncommon for high total cholesterol levels to be seen in the elderly[11].
  • Obesity: Being overweight or obese increases circulating LDL levels and triglycerides, and lowers ‘good’ or HDL cholesterol, meaning you have a greater cardiovascular risk[12].
  • Thyroid issues: If your thyroid gland produces too much or too little of the thyroid hormones needed, it can lead to abnormal blood cholesterol levels. For example, if you have an underactive thyroid, the gland isn’t producing enough triiodothyronine (T3) which is needed to help break down LDL cholesterol. Without enough T3 the body can’t remove LDL properly[13].
  • Alcohol: Heavy drinking is associated with higher blood LDL cholesterol and can result in raised triglyceride levels[14].
  • Pregnancy: During pregnancy, a mother’s cholesterol levels naturally rise as the foetus demands more for growth[15]. This rise is normal and should return to healthy levels following birth.
Dr Thom Phillips

"According to the British Heart Foundation, one in fourteen women die from coronary heart disease (CHD) in the UK per year. It may also surprise you to learn that CHD kills more than twice as many women in the UK as breast cancer so it’s a big problem. Unfortunately, often the first symptom of CHD is a heart attack."

Dr Thom Phillips

How to Improve Your Total Cholesterol Levels

In many cases, lowering cholesterol can be as simple as making some changes to your current lifestyle.

More extreme situations or people who have inherited conditions may find it more challenging to control their levels with lifestyle changes alone. Therefore, they may be advised to take statins, medicines that lower the amount of LDL cholesterol in the blood[16].

So, whether you require cholesterol-lowering medication or simply want to proactively give your cholesterol levels a nudge in the right direction, here are four ways you can help:

Get some exercise

Regular exercise increases HDL cholesterol and maintains LDL and triglycerides within normal parameters. For people who have been mostly sedentary or are new to exercise, prolonged moderate-intensity exercise is recommended. You should aim to exercise for 30 minutes per day five times per week[17].

Eat less saturated fat

Dietary saturated fat is linked to increased low-density lipoprotein and is a risk factor for cardiovascular disease[18]. You should aim to eat less:

  • Processed meat like ham, sausages, bacon
  • Fatty cuts of meat
  • Meat pies
  • Cheese
  • Cakes and biscuits
  • Butter and lard

Some types of fat are good for you and there is some evidence to suggest that they can help to lower your cholesterol levels when you replace saturated fats with them[19]. Choose:

  • Monounsaturated fats like olive oil, rapeseed oil, avocados, almonds, Brazil nuts and peanuts.
  • Polyunsaturated fats Omega-3 fatty acids like those found in oily fish (kippers, herring, mackerel, sardines, salmon, and trout) – the benefits of these come from eating the whole foods, research shows that taking dedicated Omega 3 supplements do not confer the same heart protective benefits.

Increase your fibre intake

Increasing the amount of soluble fibre in your diet can help get rid of the bad cholesterol in your body. Soluble fibre forms a gel-like substance in your gut which slows down digestion and traps cholesterol, stopping it from being reabsorbed into your bloodstream. The excess cholesterol is excreted with the rest of the waste travelling through the intestines.

Quit smoking

Smoking increases the levels of LDL and triglycerides in the blood and lowers the amount of circulating HDL cholesterol, dramatically increasing your risk of developing heart disease or having a stroke.
Within a few days of giving up, you’ll gain small improvements in your health. Within one year, your risk of heart disease will be reduced by 50%[20]. There are plenty of resources available online to help you quit smoking or your GP can help.

Limit your alcohol intake

Alcohol can put great strain on your liver, the organ responsible for the detox process and for removing bad cholesterol from the body. Therefore, cutting down your alcohol intake and keeping it below the recommended 14 units per week, will not only help lower your cholesterol levels but will have other health benefits.

Written by Leanne Edermaniger

Based in the UK, Leanne specialises in writing about health, medicine, nutrition, and fitness.

She has over 5 years of experience in writing about health and lifestyle and has a BSc (hons) Biomedical Science and an MSc Science, Communication and Society.

- Health scores calculated


Article references

  1. Gjuladin-Hellon, T. et al. (2018) ‘Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: A systematic review and meta-analysis’, Nutrition Reviews, 77(3), pp. 161–180. doi:10.1093/nutrit/nuy049.

  2. Mitsuda, N. et al. (2023) ‘Association between maternal cholesterol level during pregnancy and placental weight and birthweight ratio: Data from the Japan Environment and Children’s study’, BMC Pregnancy and Childbirth, 23(1). doi:10.1186/s12884-023-05810-3.

This article was written by Leanne Edermaniger

This information has been medically reviewed by Dr Thom Phillips

Thom works in NHS general practice and has a decade of experience working in both male and female elite sport. He has a background in exercise physiology and has published research into fatigue biomarkers.

Dr Thom Phillips

Dr Thom Phillips

Head of Clinical Services