High cholesterol - Diagnosis 

Diagnosing high cholesterol - getting a cholesterol test 

Blood cholesterol levels are measured with a simple blood test. This blood sample will be used to determine the amount of LDL (bad cholesterol), HDL (good cholesterol) and triglycerides (other fatty substances) in your blood.

You may be asked not to eat for 10-12 hours before the cholesterol test (usually including when you are asleep at night). This ensures that all food is completely digested and will not affect the outcome of the test.

Your GP or practice nurse can carry out the cholesterol test and will take a blood sample either using a needle and a syringe or by pricking your finger.


At the end of your assessment your healthcare professional will explain your results and will calculate whether you have a high, moderate or low risk of getting cardiovascular disease (heart disease or stroke) within the next 10 years.

However, this risk is not just based on your cholesterol reading – it also takes into account:

The ideal cholesterol levels for healthy adults and for those at high risk of cardiovascular disease are explained below.

Total cholesterol level

Blood cholesterol is measured in units called millimoles per litre of blood, often shortened to mmol/L.

The government recommends that total cholesterol levels should be:

  • 5mmol/L or less for healthy adults
  • 4mmol/L or less for those at high risk

In the UK in 2011, around 50% of adults had a cholesterol level above 5mmol/L. This figure has been improving steadily since the last measurement in 2003.

On average, men in England have a cholesterol level of 5mmol/L and women have a level of 5.1mmol/L.

Levels of LDL and HDL

The government recommends that levels of low-density lipoprotein (LDL) should be:

  • 3mmol/L or less for healthy adults
  • 2mmol/L or less for those at high risk

An ideal level of high-density lipoprotein (HDL) is above 1mmol/L. A lower level of HDL can increase your risk of heart disease.

Your ratio of total cholesterol to HDL may also be calculated. This is your total cholesterol level divided by your HDL level. Generally, this ratio should be below four, as a higher ratio increases your risk of heart disease.


Your doctor or nurse may also measure your level of triglycerides. Triglycerides are the fats you use for energy and come from the fatty foods you eat. You store what you do not use in the fatty tissues of your body. Excess triglycerides in the blood also increase heart problems.

Your ideal level of triglycerides should be less than 1.7mmol/l.

Who should be tested?

Your GP may recommend that you have your blood cholesterol levels tested if you:

  • have been diagnosed with coronary heart disease, stroke or mini-stroke (TIA) or peripheral arterial disease (PAD)
  • are over 40years old
  • have a family history of early cardiovascular disease (for example, if your father or brother developed heart disease or had a heart attack or stroke before the age of 55, or if your mother or sister had these conditions before the age of 65)
  • have a close family member who has a cholesterol-related condition, such as familial hypercholesterolaemia (inherited high cholesterol)
  • are overweight or obese
  • have high blood pressure or diabetes
  • have another medical condition such as a kidney condition, an underactive thyroid gland or an inflamed pancreas (pancreatitis). These conditions can cause increased levels of cholesterol or triglycerides

Page last reviewed: 15/11/2013

Next review due: 15/11/2015


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The 8 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Dizzy12 said on 16 December 2013

I was admitted to hospital in mid November 2013 with a BP of 247/127 which was dangerously high I didn't have any symptoms prior to this to give me any indication I was ill apart from the odd dizzy spell and short of breath sometimes but didn't really think there was anything wrong and I very rarely visited the G.P. as I find most G.Ps' very rude and not interested in your health unless maybe you're probably on deaths door. The only reason I went to Hospital as the Company I work for forced me to go as my eye had completely swollen up and filled with with blood around the eyeball area.

I was given medication from the Hospital on my discharge for HBP and Chlolestrol (Amlopidine and Simavastatin), 2 weeks later my G.P. gave me Lisinopril since then I've never felt so ill in my life every day I was waking up feeling sick and dizzy, horrendous stomach pains but the last 2 days the symptoms seem to be easing off a little bit, but in the last 2 weeks I have become aware of the amount of noise at work in an Engineering area and the noise is driving me crazy and I'm losing concentration which I never had a problem with apart from the last 2 weeks, today my G.P. has taken me off Simavastatin as he thinks it might be the effects of the STATINS affecting me with the noise annoyance, so I don't know whether it's a good thing or not to come off this medication and my blood pressure has gradually come down with a reading today of 150/80, has anyone got any advice for me?.

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stanliz said on 17 November 2013

Recently, found I had a soreness in left breast. Doc recommended a consultant and after ultrasound and biopsy decided it was gynocomastia - thickening of tissue. Having taken statins for 20+yrs I suggested to doc stopping to see if discomfort would desist, as condition a potential rare side effect. No difference was detected and cholesterol measured 8.4, HDL 6.5, LDL 0.9. Normally, cholesterol measures 5.2/5.5. So, if nothing else if proves the problem still exists and the effectiveness of statin treatment.

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AnAppleADay said on 11 November 2012

As it says here, there is good and bad cholesterol. Reducing fat from your diet altogether will reduce both.

It's not about how much fat, but why type of fat you have. So try replacing saturated fat in your diet with MUFA (monounsaturated fat).

Sources include avacado, seeds and nuts.

A healthy diet nearly always calls trumps!

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judip said on 05 November 2012

At a general health check because I am 65 my cholesterol was diagnosed as 6.6 by a finger prick test. I was invited back for a fasting test 4 weeks later and had a 'proper ' blood test.I had been quite shocked at the first result and was determined to do better next time. Consequently I changed my diet having looked for advice on the net. For breakfast I eat porridge oats with s/s milk, for lunch I have a low fat yoghurt and a banana and I have a normal evening meal making sure it is quite low in fat. I have an apple every evening with a few bits of dried fruit nuts and seeds to make it a bit more interesting. I eat very little bread and have cut out cheese, cakes biscuits, crisps, sweets, chocollate and puddings. I got the result of my second test today and it had gone down to 5.4 which I believe is a decrease of over18%. As well as that I have lost well over half a stone. I am thrilled and hope I can keep it up!

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HiCol said on 27 April 2012

Just diagnosed as 8.7 cholesterol level. Doc said "instant heart attack - never mind, it's a quick way to go" !!! Was told that altering my diet (which includes lots and lots of fruit and veg) would have no effect. Apart from that "advice" no help was given so what do I do ? I think it is true that the older you get the less interested the medical profession becomes ( I am just over 60).

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2am said on 17 October 2011

This page says that 'Anyone can have their blood cholesterol level tested'. When I asked my GP for a test she said it was not necessary.

Do I have a right to a test or not? Should this page not say that anyone can ask for a test but it is up to your GP whether you are given one?

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Aliwally said on 09 November 2010

I would advise anyone over 40 to have a cholesterol test as it could detect familial hypercholesterolaemia, a relatively common but underdiagnosed genetic condition. FH increases your risk of heart disease dramatically and can affect your relatives.

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conandoz said on 03 February 2010

Over a few years I have asked my local GP's for a cholesterol check and they seem so against it. It seems to me that they just want to put people off having it done.

This site does say that anyone can have it done.

Is it because of the cost?

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