High cholesterol? The cause may not be what you think

High cholesterol? The cause may not be what you think

There’s a misconception surrounding high cholesterol. That one has to be overweight and eat an excessive amount of processed foods - however, this isn’t always the case.

Anybody can have high cholesterol, whether they appear visually healthy or not.

If you have high cholesterol, you may have been told to simply alter your diet or exercise more.

While this is an effective method for many people, there are many causes of high cholesterol and it might not be your fault.

In this guide we’ll explain some of the less talked about reasons why your cholesterol could be high, dissect the myths from the facts, and what you can do to lower or maintain healthy cholesterol levels.

What is cholesterol?

Cholesterol is a fatty, waxy substance formed in your liver and can be found in some foods, but they aren’t created equally - just 25% of cholesterol comes from the food you eat while the other 75% is made by your liver.

Everybody needs cholesterol in their body, but there are two types - bad cholesterol and good cholesterol.

The bad cholesterol can build up on the walls of your arteries and increase your chances of heart disease or stroke. This is because the blood may find it difficult to reach your key organs.

Meanwhile, the good cholesterol is removed from the bloodstream and is carried straight to your liver, preventing it from building up in your arteries - the higher this is, the lower your risk of developing complications.

What typically causes high cholesterol?

High cholesterol can be caused by many things, but the most common reasons include:

  • Having an unhealthy diet, especially if you consume foods with high levels of saturated fat
  • If you smoke, due to the chemical acrolein in cigarettes lowering your good cholesterol levels, which take the bad cholesterol away from your artery walls
  • If you have diabetes or high blood pressure
  • If you have a family history of stroke or heart disease

How do I know if my cholesterol is high?

Having high cholesterol will not present any noticeable symptoms. That's why many people don’t realise they are at risk until they have a blood test.

You may only be aware you have high cholesterol if you develop heart problems or a stroke.

The only way you can measure your cholesterol levels is through a blood test which your GP may suggest if you’re over 40, overweight, if high cholesterol or heart problems run in your family, or if your cholesterol levels need to be monitored due to medication.

Other reasons why your cholesterol might be high

We’ve covered the typical reasons why your cholesterol might be high, but having high cholesterol could also be a side effect of something else.


Certain medicines can affect the amount of cholesterol in your blood. To see if any of your medications could have an effect, always check the patient information leaflet.

While some medicines will only raise cholesterol a little, some raise them significantly.

They include:

  • Diuretics (sometimes known as ‘water pills’, they are usually prescribed to lower blood pressure)
  • Corticosteroids (often known simply as ‘steroids’, they are an anti-inflammatory medicine and can be prescribed for a wide range of conditions)
  • Immuno-suppressants (medicines that lower the body’s ability to reject a transplanted organ)
  • Anti-retroviral drugs (usually prescribed to help manage HIV)
  • Retinoids (are typically used to treat skin conditions, such as the drug isotretinoin, or you might recognise it by the brand name Roaccutane)
  • Oral oestrogen (such as hormone replacement therapy)
  • Beta-blockers (usually used to manage abnormal heart rhythms)
  • Antidepressants (used to treat a variety of mental health conditions)
  • Anticonvulsants (epileptic medication)

If you’re taking any of the listed medications - don’t worry!

Your doctor will be aware of the effect your medication has before they prescribed it to you. They may even ask you for regular blood tests to make sure your cholesterol levels are in check.

Medical conditions

If your high cholesterol levels cannot be explained by any lifestyle choices or medication, your doctor will want to investigate why, as it could be a sign of an undiagnosed medical condition.

Type 2 diabetes

You probably know that type 2 diabetes causes high blood sugar. But it’s less known that it can disrupt the levels of cholesterol in your blood, especially if it’s undiagnosed or poorly managed.

If you have type 2 diabetes or insulin resistance (pre-diabetes), it’s vital to get these under control to protect your heart health.

Underactive thyroid gland (hypothyroidism)

Your thyroid gland is located in the neck, intended to produce a hormone called ‘thyroxine’ which we all need to keep our bodies running.

If you’re lacking this hormone, you will have a condition called underactive thyroid, hypothyroidism, myxoedema or Hashimoto’s disease, and it will cause your body to function too slowly.

The condition is more common in women between 40 - 50 years of age. It will develop very slowly, so you may not notice any immediate signs.

However, if you notice any of these symptoms over time such as:

  • Tiredness
  • Weight gain
  • Lacking energy
  • Slow thought and speech
  • Pins and needles
  • >Breathlessness
  • Dizziness
  • Palpitations
  • Hair loss, especially in your eyebrows
  • Dry skin

You should speak to your GP as it could be a sign you have an underactive thyroid, and possibly high cholesterol as a result.

Once treated, your cholesterol levels should return to normal within a few months.


If you are pregnant, the fat in your blood will rise - but this is normal.

It just demonstrates that your body needs the extra fat to fuel the growth of your baby.

For this reason, it’s not recommended to get a cholesterol test during pregnancy as the results won’t show your normal levels.

If you’re breastfeeding, the results will remain high for this period, and if you don’t breastfeed, the levels will get back to normal about 3 months after giving birth.


A lot changes when a woman reaches menopause. Periods stop and the ovaries no longer produce oestrogen, which causes many women to gain weight around the abdomen.

Due to this, menopause can mark a change in your cholesterol levels.

If you notice any changes, it may be time to adapt relevant lifestyle alterations or speak to your GP for advice.

Getting older

As you get older, your cholesterol levels will naturally increase and peak between the ages of 60 - 70.

It’s not completely understood why this happens, but it may have something to do with a change in lifestyle, weight or activity. Or it could be because our LDL receptors (which remove bad cholesterol from the blood) become less active as you get older.

Less common conditions

Some less common conditions could have a negative effect on your cholesterol levels - keep reading to see if any apply to you.

Chronic Kidney Disease (CKD)

Chronic kidney disease is a condition where your kidneys don’t work as well as they should, and they may eventually stop working altogether.

People with this condition often have raised cholesterol.

Nephrotic syndrome

This is a condition where your kidneys leak a large amount of protein into your urine. It's usually first diagnosed in children.

This condition may cause the swelling of body tissue, a greater chance of catching infections, and high cholesterol levels.

Liver conditions

Your liver is a very important organ when it comes to your cholesterol. It's where it’s made, processed and broken down.

Bile is a breakdown product of cholesterol and is made in the liver, stored in the gallbladder then released into the gut when we eat a meal.

Occasionally, the production of bile or its release into the gut can become blocked and develop into gallstones made from crystallised cholesterol.

The medical name for this condition is called cholestasis, where bile is unable to be transferred from the liver and can cause cholesterol levels to rise.


Gout is a type of arthritis caused by having too much uric acid in the blood.

This acid forms crystals between the joints and can cause tenderness, swelling and pain.

Having gout is often associated with the consumption of rich foods like red meat, wine and spirits, or eating too little fruit, vegetables and whole grains.

Because of this, it’s sometimes linked to heightened cholesterol levels.

Hereditary conditions

If your high cholesterol can’t be explained by secondary causes, such as medication, your doctor may want to investigate a genetic reason.

You’ll be more likely to have inherited high cholesterol if:

  • You have close family members with high cholesterol
  • Heart disease runs in your close family
  • Your close family members have an inherited blood fat condition

Listed below are some possible genetic conditions that cause very high cholesterol levels - and sometimes, all it takes is one small error in a gene to throw them off balance.

Familial Hypercholesterolaemia (FH)

The name can be a mouthful to pronounce, but if we break it down, ‘familial’ means that the condition runs in families, and ‘hyper’ means ‘too high’.

Simply put, FH is a genetic condition causing extremely high cholesterol levels. If left untreated, it may lead to heart problems at a young age.

Having a healthy lifestyle will not prevent this condition; FH affects the way cholesterol is broken down in the body, with medication typically being prescribed to help manage it.

FH occurs through the inheritance of a faulty gene from one of the parents - but there is no reason why you or your children can’t live a healthy life.

For more information about Familial Hypercholesterolaemia, visit the cholesterol charity Heart UK.

Familial Combined Hyperlipidaemia (FCH)

FCH is an uncommon condition where your cholesterol levels are overproduced. This results in a delay in the removal of triglycerides (another type of fat found in your blood).

This condition is closely associated with type 2 diabetes, as the body is forced to burn fat instead of glucose.

In turn, this increases glucose and insulin production.

Eating healthily, lifestyle changes, weight monitoring and medication are essential for those diagnosed with FCH.

You can find out more by visiting Heart UK.

Type 3 Hyperlipidaemia

This condition is rare, occurring in only 1 in 10,000 people and can closely resemble familial combined hyperlipidaemia (FCH).

To be diagnosed with this condition, you will usually have a cholesterol level of between 7 - 10mmol/L and a triglyceride level of between 4 - 8mmol/L.

You may also have deposits of fat in the creases of your hands, elbows and knees.

To read more about this condition, visit Heart UK.

Polygenic Hypercholesterolaemia

This condition is similar to Familial Hypercholesterolaemia (which is caused by just one gene), but with the additional word ‘polygenic’ which means there are multiple genes involved.

So, if you have this condition, it means that your cholesterol levels are high because of the effects of many different genes.

Genes can affect your cholesterol levels by controlling how cholesterol is taken out of the blood and how it’s broken down to be removed.

If cholesterol isn’t taken out of the blood normally, it can build up in the arteries and block them, which may result in the development of serious complications.


Although feeling stressed won’t directly impact your cholesterol levels, the way you cope with your stress levels could.

When stressed, you're more inclined to reach for unhealthy food, drink more alcohol or increase how much you smoke.

All of these factors could have a negative impact on your cholesterol levels if done too frequently. So it’s important to take steps to look after your wellbeing.

You can also get support from other organisations, such as the NHS, Mind, Samaritans or the International Stress Management Association.

Cholesterol: Myths vs Facts

There’s been a lot of information to take in from this guide. So, we’ll remind you of some myths and facts about high cholesterol.

All cholesterol is bad for you - a myth! Fact:

There are two types of cholesterol, good and bad, which your body needs to function normally to make cells and hormones.

You can only get high cholesterol if you’re old or unhealthy - a myth! Fact:

It is a fact that older people and those who eat unhealthily are more likely to suffer from high cholesterol - but if you’re young and have a healthy lifestyle, it doesn’t mean you can’t have high cholesterol either.

There are many reasons why your cholesterol could be high. It could be down to genetics, medication or a medical condition.

High cholesterol is mainly an issue for men - a myth! Fact:

Actually, it’s been shown that high cholesterol is more common in young women between the ages of 16 - 24 compared to men of the same age.

Men do take over when they reach their 50s, but after menopause, more women have high cholesterol - an example being 73% of 55 - 64 year-old women having raised cholesterol in comparison to 58% of men.

I would notice if I had high cholesterol - a myth! Fact:

High cholesterol shows no symptoms, and you may only be aware you have raised cholesterol when you have a heart attack or stroke.

The only way to know you have high cholesterol is through a blood test.

How can I lower my cholesterol?

Sometimes medication is necessary to help reduce cholesterol levels - but there are also changes you can adapt yourself to stop your cholesterol from becoming too high, and perhaps prevent it from becoming high at all.

Healthy eating

Saturated and unsaturated fat are very similar words, but they make a big difference to your cholesterol levels.

Food containing too much saturated fat - such as pies, fatty meats, dairy products, cakes, and products containing coconut or palm oil - can raise the level of cholesterol in your blood.

But by integrating food rich in unsaturated fat into your diet, it will help to reduce it.

These healthier options include:

  • Oily fish
  • Nuts
  • Seeds
  • Avocados
  • Vegetable oils and spreads
  • Food containing fibre

Additionally, trans fat - a substance found naturally in animal products and some processed food - can increase your cholesterol levels.

You can reduce your fat intake by changing the way you cook.

Rather than frying, you could consider:

  • Steaming
  • Grilling
  • Boiling
  • Poaching
  • Microwaving

Small changes can make a difference. Next time you shop choose a lean cut of meat or a low-fat dairy alternative.


Getting active helps to shift your bad cholesterol from the blood to the liver. This prevents it from clogging up your artery walls.

Doing just 150 minutes of moderate activity (enough to raise your heart rate and break a sweat) each week can improve your cholesterol levels.

To read more about the recommended exercise levels for you, visit the NHS website.

Reducing how much alcohol you drink

Alcohol is processed through the liver, the same organ responsible for creating cholesterol.

It’s broken down and rebuilt into blood fat, therefore increasing the bad cholesterol levels in your blood.

Some studies argue that drinking red wine may lower your risk of heart disease due to its antioxidant properties.

But alcohol is still more likely to do you more harm than good. So, it’s wise to drink no more than the recommended number of 14 units per week.

If you need support to help you cut back or stop drinking altogether, visit your GP, Drinkaware, or the NHS website.

Stopping smoking

Cigarettes contain chemicals that lower the amount of good cholesterol in your blood, and can double your chances of developing a heart attack or stroke.

By stopping smoking, you will feel healthier within a matter of hours.

After 1 year, your risk of heart disease will be halved. After 15, it will be similar to that of a non-smoker.

There is plenty of support out there to help you stop smoking, like patches, chewing gum and medication, or you can get advice from your GP or local Stop Smoking Service, the Smokefree website, or the NHS Smoking Helpline. 


If you have high cholesterol, your doctor may have offered you a medicine called statins.

Statins work by blocking a substance in your body which makes cholesterol, effectively lowering the cholesterol count in your blood.

You will usually be offered this medication if you have been diagnosed with a form of cardiovascular disease (CVD), if your medical history suggests that you may develop CVD, or if lifestyle alterations have not lowered this risk.

New developments

In September 2021, a new cholesterol-lowering drug called inclisiran was released. It's administered by injection twice a year.

Plus, there’s no need to take long trips to the hospital, either. You can simply contact your GP to request a prescription.

Researchers say that the drug can safely cut cholesterol by 50%, and if combined with a statin, this number could rise to 75 - 80%.

Many have hailed this drug as ‘life changing’ as it’s expected that 30,000 people could avoid premature death from heart disease and strokes.

High cholesterol can affect anybody - old, young, fit or unhealthy - and can produce dangerous complications if not managed.

Most likely, you won’t know you have high cholesterol unless you have a blood test. That's why it’s important to live a healthy lifestyle, as each small change will lower your risk.

Need more information? Visit the cholesterol charity Heart UK or the NHS website.

Alexandra Moses - Medical Content Writer
James O'Loan - CEO & Superintendent Pharmacist
James O'Loan , CEO & Superintendent Pharmacist on 11 July 2023
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