Updated 31 July 2014

Understand the cholesterol numbers

What do the different cholesterol levels mean? Here is a list of suggested interventions based on the results of total cholesterol and HDL levels.

Understanding cholesterol numbers

If a lipid disorder is found or suspected, you should ideally change your lifestyle for at least four weeks. Then a full lipogram (blood test analysing your lipid profile) should be performed to decide about the type of disorder you have, what its risks are and what the best choice of medication is.

Here is a list of suggested interventions that will in most cases be prescribed based on the results of your total cholesterol count, your HDL and LDL level and your triglyceride level. The numbers are guidelines to decisions and are not precise cut-offs for decisions.

Total and HDL cholesterol



Cholesterol levels

Remarks and suggested action 


Total cholesterol below 5 mmol/L;
HDL higher than 0.9 mmol/L

- 35% of heart attacks occur in this range.
- If your HDL is higher than 0.9 mmol/L and you don’t have any other risk factors, you don’t have a significant risk for heart disease or stroke. Have your cholesterol retested in five years or if your health changes in any other way that may increase the risk of heart disease.

- If your HDL is higher than 0,9 mmol/L and you smoke, suffer from high blood pressure or have any other risk factor for heart disease or stroke, the doctor will calculate your risk for these diseases. One popular risk calculation system is called the Framingham risk score.

- If your HDL is below 0.9 mmol/L, your triglyceride levels will be analysed.
- Follow a healthy lifestyle

Borderline to high

Total cholesterol 5 -7,5 mmol/L

- If your HDL is higher than 0,9 mmol/L and you have no other risk factors for heart disease or stroke, your risk for a heart attack within 10 years is probably lower than 20%. Visit the doctor for follow-up tests every six to twelve months. Change to a healthier lifestyle: exercise, low-fat diet and no smoking.

- If your HDL is lower than 0,9 mmol/L and you have other risk factors for heart disease or stroke such as smoking or hypertension, the doctor will calculate your risk of suffering a heart attack within the next 10 years. If the risk is greater than 20%, a lipid-lowering drug may be prescribed. Also change to a healthier lifestyle.

High risk

Total cholesterol 7,5 mmol/L or higher

- The doctor will do a detailed assessment of your blood tests to characterise the disorder and its causes.
- He will probably describe a lipid-lowering drug and advise lifestyle changes.

- Any other risk factors for heart disease or stroke should also be evaluated and treated by the doctor.

LDL cholesterol


Description of risk

LDL level

Remarks and suggested action


Lower than 3 mmol/L

This is the ideal level when there is no vascular disease present.

Borderline to high

3-5 mmol/L

- The doctor will investigate the cause(s) of your higher LDL cholesterol, such as underlying diseases, your diet or drugs you may be taking.

- Lifestyle changes such as diet and exercise will be prescribed to lower your cholesterol level.

- If the doctor calculates that your risk of heart disease within the next 10 years is higher than 20%, she will prescribe a lipid-lowering drug.


higher than 5 mmol/L

- The doctor should perform a clinical examination.

- Laboratory tests should be done as needed.
- The doctor will investigate the cause(s) of your high cholesterol. For instance, a genetic disorder is probably present.

- A lipid-lowering drug combined with diet modification and exercise may be recommended.
- If the doctor finds that you have atherosclerotic vascular disease, your target LDL cholesterol should be lower than 2.5 mmol/L. However, this could be difficult to achieve with lipid-lowering drugs alone.
- One LDL measurement is not sufficient for the doctor to decide on the best treatment. Your LDL cholesterol will therefore be measured twice within a one- to eight-week period. If the measurements differ by more than 0.8 mmol/L, a third test will be performed and the doctor will base treatment on the average of the three tests.

Description of risk

Triglyceride level

Remarks and suggested action

Borderline to high

 5-15 mmol/L

-          You have a higher risk of vascular disease.

-          The doctor will investigate possible causes such as diabetes, a very fatty diet, obesity and alcohol.

-          A low-triglyceride diet will be prescribed.

-          The doctor may prescribe statins (lipid-lowering drugs) and/or fibrates (triglyceride-lowering drugs). If the triglycerides are higher than 15 mmol/L there is a risk of pancreatitis and urgent attention is required to ensure that the level is lowered effectively.



Higher than 15 mmol/L

-          Vascular disease could occur in the long term, but there is a shorter-term risk of pancreatitis (with severe abdominal pain as a symptom) that could lead to severe impairment of lung and kidney function and even death.

-          The doctor will prescribe a very low-triglyceride diet and fibrates.


Reviewed by Prof David Marais, head of the Lipid Clinic at the University of Cape Town and Groote Schuur Hospital, September 2010.

The Heart and Stroke Foundation




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