Your guide to 11 different types of blood tests

1. Troponin

Troponin is a protein that’s released into your bloodstream when the heart muscle is damaged.

If you have chest pain, you will usually be given a blood test to check the level of troponin in your blood.

Higher levels than normal could be a sign of a heart attack. However, you may still have had a heart attack even if your troponin levels are low.

A new type of test, known as a high-sensitivity troponin test, can measure the same protein but at much lower levels.

This can help when diagnosing women with a heart attack, as they tend to produce less troponin than men.

Troponin levels are tested in hospital, and the results should be available quickly. This helps doctors give you timely treatment to stop further damage to the heart. 

• Learn more about troponin. 

2. Cholesterol (lipid profile)

This test measures your total cholesterol level, as well as how much ‘good’ and ‘bad’ cholesterol and another type of fat called triglyceride is in your blood.

If your ‘bad’ cholesterol levels are too high, you may be prescribed a statin to lower it to help reduce your risk of having a heart attack or stroke.

This test is also a good way to see if your medicine is reducing your ‘bad’ cholesterol levels, and check if your dose needs to be increased.

Many people over the age of 40 only need their cholesterol tested once a year, but your doctor may want to keep a closer eye on it if it remains high.

You may have this test at your GP surgery, or in hospital if you have had a heart attack. 

• Read more about why you should get your cholesterol levels tested. 

3. Blood sugar (HbA1c) 

An HbA1c blood test checks your blood sugar (glucose) level. If your blood sugar levels are high, it’s a sign that you have diabetes.

If the levels are slightly higher than normal but do not meet the criteria for diabetes, your doctor might say you have pre-diabetes or ‘borderline’ diabetes.

This means you are still at risk, but if you make some lifestyle changes such as losing weight to a healthy level, your blood sugar levels may go back to normal.

Before some tests, you may be asked not to eat any food, or drink anything but water for 12 hours before.

• Discover why it’s important to know your blood sugar levels. 

4. Full blood count (FBC)

A full blood count test looks at different cells in your blood.

This can identify if you have anaemia, which is a lack of red blood cells carrying oxygen around the body.

It can also help to rule out or confirm infections and viral conditions, such as myocarditis, which is when the heart muscle becomes inflamed.

5. Urea and electrolytes (U&E)

This checks for minerals called electrolytes in the blood such as sodium (salt), potassium and magnesium.

If the levels are too high or too low, this can cause abnormal heart rhythms (arrythmias), so it’s important to adjust them to healthy levels.

The blood test also looks at your urea levels, which is a protein normally broken down in the kidneys.

A high level of urea in the blood could be a sign of kidney problems, which can affect your heart too.

Some heart medicines, such as ACE inhibitors, can affect your kidneys, so this test will help your doctor decide if it is safe to increase your dose.

• Find out more about the link between kidney and heart diseases.

6. International Normalised Ratio (INR)

This test measures how long your blood takes to clot.

You’ll have this test regularly if you take an anticoagulant (a medicine that prevents blood clots), such as warfarin.

The INR result will help your doctor decide how much medicine you need to take. Sometimes it takes a while to get the right INR level, so you may find your doctor changes your medicine doses until your INR is at the right level. 

You may attend an anticoagulation clinic for your tests, or your GP practice if they’re able to do them.

Once your INR levels are stable, you can ask about getting your own INR testing kit to use at home if it’s difficult for you to attend regular testing.

• Get more information on warfarin. 

7. B-type Natriuretic Peptide (BNP) 

If you’re showing signs of heart failure, such as swollen ankles or feeling short of breath, you may be given a blood test to check your BNP levels.

High levels of this hormone can be used to help diagnose heart failure and tell your doctor how severe it is. 

8. Thyroid test 

Problems with your thyroid (a gland that releases hormones in your body) can lead to some heart problems such as a fast or slow heart rate.

If you experience these symptoms, you may be given a thyroid test to check the level of hormones released by the thyroid in your blood.  

This test can diagnose an underactive or overactive thyroid. 

9. Liver blood tests

These used to be called liver function tests (LFTs) and are done to make sure your liver is working properly.

The test looks at several different enzymes and proteins, which can be higher or lower than normal if the liver is damaged.

However, an abnormal test result does not always mean that your liver is not working properly. 

10. Arterial blood gas 

You may be given a blood gas test if you’re having trouble breathing or have lung problems.

Blood is taken from an artery in the wrist to check your blood’s acid balance, and levels of oxygen and carbon dioxide.

This test is usually only done in places like A&E and intensive care units. 

11. Group and save test

Also known as a ‘group and screen test’, you’ll be given this test if you need a blood transfusion because you’re having surgery or have severe anaemia.

It finds out your blood group and checks for antibodies (proteins that make up your immune system) that can affect a transfusion.

This test needs to be done in hospital less than 72 hours before a blood transfusion. 

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