How do cholesterol tests work, and what do I need to know?

December 15, 2019 3 min read

If your doctor suspects you might have high cholesterol, they will ask you to come in for a test to confirm it. Tests for blood cholesterol levels are a regular part of many people's lives and nothing to worry about. Here's what you need to know.

 

What is a cholesterol test?

Cholesterol tests generally take the form of a blood test to measure the levels of cholesterol and triglycerides contained in the blood.

It will measure:

 

  • Total blood cholesterol levels
  • High Density Lipoprotein (HDL, or good cholesterol) levels
  • Low Density Lipoprotein (LDL, or bad cholesterol) levels
  • Triglycerides, fats used for energy storage in the body

 

By measuring blood levels of the above factors, your doctor can assess how much of a risk factor you are for high cholesterol, and what can be done to minimise the issues that can come from having high cholesterol, which include strokes and heart attacks.

 

Do you need to fast when having a cholesterol blood test?

Yes. Your doctor will tell you for how long before the test you can't eat anything, but it's generally around 14 hours.

Also bear in mind that alcohol shouldn't be drunk within 48 hours of your blood test.

These measures are so that your doctor can draw an accurate blood cholesterol level, rather than have it warped by recent meals.

 

What happens during a cholesterol blood test?

A cholesterol blood test is similar, if not identical to any blood tests you might have had before.

Your health practitioner will apply a tourniquet to your arm to restrict blood flow and make it easier to find a vein, then insert a needle and draw a small amount of blood.

Once this is done, the test is effectively over. The needle and tourniquet will be removed, and the entry point will be covered with a cotton ball and a band-aid to prevent any further blood from leaking from it.

The whole process will only take a few minutes, and won't impact the rest of your day in any way.

 

Can I drink before my blood test?

You can, but you should only drink water.

Avoid sugary drinks, and as we said above, absolutely no alcohol.

 

How long will my test take?

A few minutes, like a normal blood test.

 

Will my test hurt me?

It shouldn't. There may be slight discomfort from the needle, but a professional phlebotomist will be able to perform it without any major issues.

If you have anxiety about injections, be sure to discuss this with your doctor beforehand.

 

Do I need to do anything after my test?

Not unless advised by your doctor. Once the test is done, you can eat and drink as normal, and if your doctor advised you to stop any medication during your test, this can also be restarted.

 

What values should I be looking for in my test results?

Different organisations have different healthy guidelines, but as a general rule, here's what you should be looking for when your results come back:

 

Total cholesterol level

Good: Less than 200mg

Borderline: 200 to 239mg

At risk: Over 240mg

 

High Density Lipoprotein (HDL)

Good: More than 60mg

Bad: Less than 40mg

 

Low Density Lipoprotein (LDL)

Preferred: Less than 100mg

Good: 100 -130mg

Cause for concern: 130 – 160mg

High: 160 – 190mg

Very high: Above 190mg

 

Triglycerides

Normal: Under 150mg

Approaching high: 150 – 200mg

High: 200 – 500mg

Very high: Above 500mg

 

Are there any risks to a cholesterol test?

No, not generally. You will normally have bruising at the site of the injection, but this should fade within several days.

You may also feel faint during your blood test, due to the blood vessels dilating and your heart slowing. This is an entirely standard reaction, and will pass in a few minutes. Your medical practitioner will advise you to relax and sit or lie down until it passes.

Very very rarely, a blood test can cause an infection.

 

When should I have a cholesterol test?

Your doctor will advise you on the correct time to have a cholesterol test. Make sure to discuss your cholesterol with your healthcare provider if you feel like you have a cause for concern.

 

Important information: The information provided on this website is of a general nature and information purposes only. It does not take into account your personal health requirements or existing medical conditions. It is not personalised health advice and must not be relied upon as such. Before making any decisions about your health or changes to medication, diet and exercise routines you should determine whether the information is appropriate in terms of your particular circumstances and seek advice from a medical professional.