Bone marrow test

This test checks whether there are cancer cells in your bone marrow.

You might not need to have a bone marrow test if you have already had a PET-CT scan.

What is a bone marrow test

Bone marrow is spongy tissue and fluid that is inside your bones. It makes your blood cells. A doctor or specialist nurse removes a sample of bone marrow, usually from your hip. Doctors then look at this under a microscope.

Diagram showing a bone marrow biopsy

You have the test in the outpatient department of the hospital. You have a local anaesthetic to numb the area. This means you are awake, but the test shouldn't be painful.

Some people prefer to have some sedation before the test so that they are a bit drowsy. Some hospitals may use gas and air (Entonox) to relax you instead of sedation.

Types of biopsy

There are 2 main types of bone marrow test: 

  • bone marrow aspiration
  • bone marrow trephine biopsy

Aspiration means the doctor or nurse sucks some liquid bone marrow up into a syringe.

A bone marrow trephine means that they remove a very thin 1 or 2cm long core of bone marrow in one piece.

You usually have both of these tests done at the same time. They give some of the same information to the doctor, but there are differences. The bone marrow trephine shows the structure of the bone marrow inside the bone, whereas the aspiration takes just the bone marrow cells.

Preparing for your bone marrow test

Check your appointment letter for how to prepare for your bone marrow test.

You are usually able to eat and drink beforehand. Take your medicines as normal.

If you are taking any blood thinning medicines you might need to stop these before the test. Your doctor will tell you when to stop taking them.

What happens

Your doctor will ask you to sign a consent form once they have given you information about the procedure. This is a good time to ask any questions you have. When you arrive at the clinic a staff member will ask you to take off your clothes and put on a hospital gown.

You usually lie on your side with your knees tucked up into your chest. First the doctor or nurse cleans the area with some antiseptic fluid, which can feel cold.

Then you have a local anaesthetic injection into the skin over the biopsy site. When the area is numb, the doctor or nurse puts a thin needle in through the skin. It goes into the bone, where the marrow is. The needle going into the hip bone can be painful but this only lasts a short time.

The doctor or nurse sucks a small amount of liquid bone marrow into the needle, using a syringe. You feel a pulling sensation when they start drawing the bone marrow cells out. Some people have a sudden, sharp pain.

They take this needle out and put a slightly thicker one in. The doctor or nurse turns the needle back and forth while pushing it further into the marrow. The aim is to get a small amount of marrow out in one piece. Once it is in far enough, they gently pull out the needle, containing its core of marrow.

The whole test takes 15 to 20 minutes.

After your bone marrow test

If you have a sedative, you need to stay at the hospital for a few hours until it has worn off. And you need someone with you so that you don't have to go home on your own. You can go home that day if you are feeling well enough.

The area is looked at by the nurses before you go home. You have a dressing over the area, which you should keep on for 24 hours. If you notice any bleeding, apply pressure to the area. You can do this by lying on your back. Contact the hospital if the bleeding doesn't stop.

After the test, your hip might ache for a couple of days. You may need some mild painkillers such as paracetamol to take at home.

Possible risks

A bone marrow test is a safe procedure but your nurse will tell you who to contact if you have any problems afterwards. Your doctors will make sure the benefits of having a bone marrow test outweigh these possible risks.


You might have some bleeding afterwards. If you notice bleeding when you’re at home and it carries on for more than 15 minutes, contact the hospital.


There is a small risk of infection in the test area. Let your doctor know if you have a temperature or the area becomes red and sore. 

Getting your results

You should get your results within 1 or 2 weeks. You normally get them at your next clinic appointment.

Waiting for test results can be worrying. You might have contact details for a specialist cancer nurse. You can get in touch with them for information and support if you need to. It may help to talk to a close friend or relative about how you feel.

You can also call the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday.
Last reviewed: 
29 Sep 2020
Next review due: 
29 Sep 2023
  • The Royal Marsden Manual of Clinical Nursing Procedures, 9th edition
    L Dougherty and S Lister (Editors)
    Wiley-Blackwell, 2015

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