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HealthInfo Canterbury

Bone marrow biopsy

A bone marrow biopsy is when a small sample of bone marrow is taken and looked at under the microscope to see if there's anything wrong. This test will help to confirm your diagnosis and plan any treatment. It's done by a doctor who'll explain the test to you. It will take 20 to 30 minutes to complete. It is a good idea to go to the toilet beforehand.

The doctor takes a small sample of bone marrow from the back of your hip bone or very rarely from your breastbone.

Before the doctor takes the sample, they'll ask you to lie on your side. The skin over your hip bone will be cleaned and local anaesthetic will be injected to numb the area.

The doctor will then pass a small needle through your skin and into your bone. The doctor will draw a sample of your bone marrow fluid up into the syringe. This is called bone marrow aspiration.

You may need a small piece of bone marrow removed. This is called a trephine biopsy. A special type of needle is used to do this. The doctor passes it through your skin into your bone. The doctor then gently turns the needle back and forth and when they remove the needle, a small piece of bone marrow comes out.

If you're finding the procedure too painful, you may be given Entonox gas to help you relax and to provide pain relief. If this happens, you shouldn't drive for the rest of the day. If possible, it's best to arrange for someone else to drop you off and pick you up whether or not the gas is used.

Preparing for your bone marrow biopsy

If you're taking blood thinners such as warfarin, dabigatran (Pradaxa) or rivaroxaban (Xarelto) and you haven't received instructions on what to do, please contact the Haematology Service using the contact details below. Usually, you'll need to stop the medication for two to five days before the procedure.

Unless it has been prearranged that you'll be having intravenous sedation, you can eat and drink as normal before the procedure.

Cultural needs

For some people, it's important to have their bone marrow returned to them after it has been tested. For example, many Māori choose to have their bone marrow returned. This is so it can be blessed and buried in a significant place. If you would like this option, please speak with your doctor at the bone marrow biopsy procedure.

Sometimes your bone marrow can't be returned since the laboratory has to use all of it. But speak up if having your bone marrow returned is important to you. The Haematology Service will try to get it back to you wherever possible.

If you have any special needs, it's important that you give at least five days’ notice. Examples of special needs include:

Contact the Haematology Outpatient nurses on (03) 364-0824 if you want:

After your bone marrow biopsy

Possible complications


It can take a few weeks for the results of your bone marrow biopsy to come through. When your results are available, your doctor will advise you of them either in clinic or over the phone.

Contacting the Haematology Service

For non-urgent nursing advice, phone Haematology Outpatients on (03) 364-0824, Monday to Friday, 7.30 am to 4 pm.

If you're feeling unwell, have a fever or other concerns, contact:

Written by the Canterbury Regional Cancer and Haematology Service. Adapted by HealthInfo clinical advisers. Last reviewed May 2020. Last updated May 2021.


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Review key: HIBMB-29828