What is total cholesterol?

Six out of ten adults have raised cholesterol and many people are completely unaware they have it. That’s because it tends not to cause any symptoms. But it can put you at risk for serious health conditions like heart disease and stroke.  

It’s useful to know what total cholesterol is as well as how different types of cholesterol impact your health.   

In this article, we cover:  

• What is total cholesterol? 
• What are the different types of cholesterol? 
• Why take a total cholesterol blood test? 
• How often should I check my cholesterol? 
• What should my cholesterol levels be? 
• What causes high cholesterol?
• What are the risks of high total cholesterol? 
• Do cholesterol levels differ for men and women?
• Can pregnancy affect my cholesterol levels?
• How can I lower my cholesterol? 
• What should I do if my cholesterol is raised? 

What is total cholesterol?

Cholesterol is a lipid, a type of fatty substance. Some cholesterol is produced by the liver and the rest comes from the food we eat. Despite often getting bad press for its association with heart disease and stroke, cholesterol is an essential component for the body to function normally.  

Cholesterol is found in every cell in the body, which helps to maintain the structure of cell membranes. It’s also an important building block for cholesterol-based hormones and vitamins, like testosterone, oestrogen, and vitamin D.  

Total cholesterol is the overall amount of cholesterol in your blood including both good and bad cholesterol.  

What are the different types of cholesterol?

The main types of cholesterol are: 

• Low-density lipoproteins (LDLs) — “bad cholesterol” 
• High-density lipoproteins (HDLs) — “good cholesterol” 

Good cholesterol collects fatty substances from the arteries and organs and carries them back to the liver where they can be flushed from the body. That’s why higher levels of HDL can lower your risk of heart disease and stroke.  

On the other hand, bad cholesterol carries fatty substances from the liver (where it’s made) to various tissues where it can be used by the cells. If you have a surplus of bad cholesterol, it builds up around the organs and along the blood vessels — this can block up the arteries and put you at greater risk of heart disease and stroke.  

Your blood test may also include a different type of lipid, called triglycerides. Triglycerides are a type of fat that store unused calories as an energy source for the body when it needs it. Similar to other bad cholesterol, having high levels of triglycerides can be harmful to your health.  

Why take a total cholesterol blood test?

Your cholesterol levels are directly related to your heart health. They can help you to calculate your ten-year risk of having a heart attack or stroke by using the QRISK3 tool.  

A Cholesterol Blood Test will usually show you your ratio of good and bad cholesterol — it can help you to identify whether changes to your diet may benefit your health. 

How often should I check my cholesterol?

The only way to check your cholesterol levels is with a blood test.  

It’s generally a good idea to check your cholesterol every few years or more frequently if you are known to have high cholesterol or another condition that puts you at increased risk of heart disease. Some people may like to check their cholesterol more often, especially if they are making lifestyle changes and want to track their progress. 

You’ll usually be offered a cholesterol test if you: 

• Are aged between 40 and 74 — it’s included every five years with the NHS health check 
• Are at high risk of heart disease — e.g., if you have a family history, you’re overweight, you smoke, or you have diabetes 
• Have been diagnosed with heart disease or other related illnesses like stroke or peripheral vascular disease 
• Are taking medicines to lower your cholesterol — it’s usually tested every year 
• Have a close relative with familial hypercholesterolaemia 

You can check your cholesterol levels at home with our Cholesterol Blood Test — a simple finger-prick blood test. 

What should my cholesterol levels be?

The following cholesterol targets are given as a guide [1]:  

	Lower-risk individuals	Higher-risk individuals
Total cholesterol	≤5 mmol/L	≤4 mmol/L
HDL cholesterol	≥1 mmol/L for men and ≥ 1.2 mmol/L for women (ideally around 1.4; very high levels may not offer any additional protection)	≥1 mmol/L for men and ≥ 1.2 mmol/L for women (ideally around 1.4; very high levels may not offer any additional protection)
LDL cholesterol	≤3 mmol/L	≤2 mmol/L*
Non-HDL cholesterol	≤4 mmol/L	≤2.6 mmol/L*
Triglycerides	≤2.3 mmol/L	≤2.3 mmol/L

 

If you're at an increased risk of heart disease, your doctor may set specific targets for you.

*In December 2023, NICE issued new guidelines recommending an LDL cholesterol goal of less than or equal to ≤2 mmol/L and a non-HDL cholesterol goal of less than or equal to ≤2.6 mmol/L for individuals with a higher risk of cardiovascular disease [2]. This means that more people are likely to be offered statins or lipid-lowering therapy to prevent further disease. 

Total cholesterol to HDL ratio 

Another useful measurement is your ratio of total cholesterol to HDL cholesterol ratio (TC: HDL). This is because HDLs can somewhat counter the negative effects of bad cholesterol. A higher ratio means a higher risk of heart disease.  

The ideal total cholesterol to HDL ratio is less than 4.  

What causes high cholesterol?

Several factors can increase your risk of high cholesterol, including:

• Smoking – smoking makes your LDL cholesterol ‘stickier’ – so it clings to your artery walls and also lowers your level of HDL cholesterol [3].
• Diet – medical professionals currently believe that eating too much saturated fat (found mainly in animal foods) can raise your cholesterol.
• Obesity – having a body mass index (BMI) of 30 or greater puts you at a higher risk of having high cholesterol.
• Lack of exercise – exercise helps boost the amount of your body’s HDL, or ‘good’, cholesterol [4].
• Age – as you age, your liver becomes less able to remove cholesterol from the blood, increasing the likelihood of having high cholesterol [5].
• Menopause - women may find that their cholesterol levels rise during menopause. Research has found that menopause is associated with a more “atherogenic” (potentially damaging) lipid profile [6]. It may be beneficial that women monitor cholesterol levels as they enter the menopausal transition to assess their risk of heart attack and stroke.
• Genetics – a genetic predisposition to high cholesterol levels and a family history may increase your risk.
• Thyroid disease -hormones produced by our thyroid gland play a major role in the regulation of metabolism and aid the breakdown of fats, including cholesterol. If your thyroid gland is under or overactive, the body's ability to process cholesterol can be affected, and this may lead to hypercholesterolemia (high cholesterol levels).
• Diabetes -people with uncontrolled diabetes, who have persistently high sugar levels in their bloodstream are more likely to have unhealthy cholesterol and triglyceride levels.

What are the risks of high total cholesterol?

If you have high cholesterol, it can build up in the artery walls, restricting the blood flow to your heart, brain, and the rest of your body. These fatty deposits, known as plaques, can rupture and encourage the blood to clot. If a clot travels to the heart or brain it can cause a heart attack or stroke.  

Raised cholesterol increases your risk of:  

• Angina 
• Heart attacks 
• Stroke 
• Transient ischaemic attacks (TIA) — often known as a mini-stroke 
• Peripheral vascular disease (PVD) — pain, ulcers, and numbness in the legs and feet 

PVD, if left untreated, can lead to serious and potentially fatal problems.   

Do cholesterol levels differ for men and women?

Women naturally have higher HDL cholesterol levels than men due to hormonal differences [7]. Women should aim for an HDL cholesterol level above 1.2mmol/L while men should aim for above 1mmol/L.

Can pregnancy affect my cholesterol levels?

During pregnancy, cholesterol and triglyceride levels increase naturally. As the pregnancy develops, there is increased availability of nutrients for the placenta to support the growth and development of the baby [8].

This temporary increase is normal and poses no harm to the baby or mum. We recommend having your cholesterol levels checked three months after you have given birth.

How can I lower my cholesterol?

Fortunately, in most cases, cholesterol can be lowered by making changes to your diet and lifestyle.  

For people with inherited conditions, like familial hypercholesterolaemia, it may be difficult to lower cholesterol levels into the normal range with lifestyle changes alone. You may be advised to take cholesterol-lowering medication. However, many of these suggestions will still be beneficial to overall health alongside any medication.  

Four top tips to reduce cholesterol:  

1. Eat less fatty food — include plenty of fresh fruit and vegetables and switch to healthier fats that can raise your HDLs (you could even try something like the Mediterranean diet)
2. Exercise regularly — aim for at least 150 minutes of moderate exercise a week 
3. Stop smoking — smoking can raise your cholesterol and significantly increase your risk of heart disease and stroke 
4. Cut back on alcohol — try to avoid drinking more than 14 units a week 

Try the following meal substitutions to lower your cholesterol:  

Meat pies, sausages, bacon, fatty meat	Turkey, lean chicken, and oily fish (like mackerel and salmon)
Butter, lard, and ghee	Extra virgin olive oil (or refined olive oil for temperatures over 200°C)
Full fat milk	Skimmed, 1% or semi-skimmed dairy milk, or plant-based milk
Cakes and biscuits	Fruit-based desserts and plain biscuits (e.g., rich tea)
Most cheeses	Low-fat cheeses like cottage cheese, Quark, or reduced-fat cheese
Double cream	Soya single alternatives
White rice, bread, and pasta	Wholemeal alternatives

What should I do if my cholesterol is raised?

If your cholesterol levels are raised, it’s best to discuss this with your GP, particularly if you have other risk factors, like high blood pressure, diabetes, or if you smoke. 

It’s likely your GP will recommend lifestyle changes for a few months before repeating your cholesterol measurement. If there has been little improvement and you’re deemed high risk, they may suggest cholesterol-lowering medication, such as a statin.
 

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References 

1. NHS. 2022. High cholesterol - Cholesterol levels. [online] Available at: https://www.nhs.uk/conditions/high-cholesterol/cholesterol-levels/ [Accessed 10 June 2022]. 
2. NHS. 2023. Millions of people with cardiovascular disease could benefit from a new cholesterol treatment target recommendation. [online] Available at: https://www.nice.org.uk/news/article/millions-of-people-with-cardiovascular-disease-could-benefit-from-a-new-cholesterol-treatment-target-recommendation
3. Heart UK. Quit smoking. [cited 2020 22nd October]; Available from: https://www.heartuk.org.uk/healthy-living/quit-smoking.
4. Steven Mann, Christopher Beedie, and Alfonso Jimenez, Differential effects of aerobic exercise, resistance training and combined exercise modalities on cholesterol and the lipid profile: review, synthesis and recommendations. Sports Medicine, 2014. 44(2): p. 211-221.
5. AE Morgan, et al., Cholesterol metabolism: a review of how ageing disrupts the biological mechanisms responsible for its regulation. Ageing research reviews, 2016. 27: p. 108-124.
6. Panagiotis Anagnostis, et al., Effects of menopause, gender and age on lipids and high-density lipoprotein cholesterol subfractions. Maturitas, 2015. 81(1): p. 62-68.
7. Jacques E Rossouw, Hormones, genetic factors, and gender differences in cardiovascular disease. Cardiovascular Research, 2002. 53(3): p. 550-557.
8. Heart UK. Pregnancy and Blood Fats. [cited 2020 22nd October]; Available from: https://www.heartuk.org.uk/cholesterol/pregnancy-and-blood-fats.