Bone marrow test (Bone marrow aspiration and trephine biopsy)

What is a bone marrow test (aspiration and biopsy)?

A bone marrow test looks at the spongy tissue inside your bones where blood cells are made. A blood specialist (haematologist) usually takes two samples from the back of your hip bone: a small amount of the liquid marrow (the aspiration) and a tiny solid core of marrow and bone (the trephine biopsy). The samples are sent to a laboratory and examined under a microscope.

It is done to find out why blood counts are abnormal, to diagnose or stage blood conditions such as anaemia that has no clear cause, low or high cell counts, lymphoma, myeloma or leukaemia, and to check how treatment is working.

The test tells the specialist a great deal about how your marrow is working, but it is one piece of the picture. Results are usually combined with blood tests, scans and sometimes genetic tests before any diagnosis is confirmed.

It does not treat anything. It is a way of gathering information so the right plan can be made.

Types, options & approaches

There may be different ways to do this. The right approach depends on the clinical question and your circumstances.

Options at a glance

These are the main approaches described in this guide. The right option depends on the diagnosis, your goals and what your clinician thinks is safe.

Preparing for your procedure

• Tell the team about all medicines, especially blood thinners (such as warfarin, apixaban, rivaroxaban, clopidogrel or aspirin), as these may need checking or adjusting first.
• Mention any bleeding problems, easy bruising, or a known platelet or clotting disorder.
• Say if you have had a bad reaction to local anaesthetic before.
• Ask whether you can eat and drink as normal — you usually can, unless sedation is planned, when you may be asked to fast.
• If sedation is planned, arrange for someone to take you home and stay with you, and do not plan to drive.
• Wear comfortable, loose clothing so the hip area can be reached easily.
• You can usually bring someone with you for support; ask the clinic about their policy.
• Ask how and when you will get your results before you leave.

What happens

You will usually lie on your side or front on a couch. The skin over the back of your hip is cleaned, and local anaesthetic is injected to numb the skin and the surface of the bone. This part can sting for a few seconds.

The specialist passes a needle through the numbed skin into the bone. For the aspiration, a small amount of liquid marrow is drawn up into a syringe — many people feel a brief, strong pulling or cramping sensation for a second or two as this is done. For the trephine biopsy, a slightly wider needle is used to take a small solid core of marrow and bone; you may feel pressure and a pushing sensation.

The needle is then removed and firm pressure is applied to stop any bleeding before a dressing is put on. You will usually be asked to lie still for a short time. The samples are sent to the laboratory. The test itself often takes about 20 to 30 minutes.

Is this procedure right for me?

A good consultation should explore whether it's the right choice for you now — including reasons to wait or consider something else.

Before you decide

Use this as a shared-decision checklist. The aim is not just “can this be done?”, but whether it is right for you, now, with the risks and alternatives clearly understood.

Comfort, sedation or contrast choices

If local anaesthetic, sedation, contrast or pain relief is used, ask what is planned, why, and what it means afterwards.

Serious problems after a bone marrow test are uncommon. The main one to be aware of is bleeding, which is more likely if you have a myeloproliferative condition, take aspirin or other blood thinners, or have a low platelet count. Tell the team about any of these beforehand so they can plan safely, and report bleeding that soaks through the dressing or a swelling that keeps growing.

Published figures to discuss

Bone marrow tests are minor procedures and serious complications are uncommon, but they are not zero. UK surveys of blood specialists give a useful guide to how often serious events happen, with bleeding being the main concern, especially in people with certain blood conditions or on blood thinners. These figures come from voluntary reporting and may under-count minor events.

These are literature figures, not a personalised prediction. Your own risks and likely benefits depend on your circumstances, your health, and how your care is carried out and followed up.

What happens afterwards

There is no major recovery, but the area can ache for a few days, much like a deep bruise. Most people go home soon after the test and return to normal activities within a day or two, avoiding anything that presses hard on the area.

• Aching or tenderness at the site, like a deep bruise, for a few days
• A small bruise or a little dried blood on the dressing
• Feeling a bit tired after an anxious appointment
• Waiting one to two weeks, or longer, for the full report

Aftercare

• Keep the dressing clean and dry for the time you are advised (usually 24–48 hours).
• Take simple pain relief such as paracetamol if you need it, unless told otherwise.
• Avoid heavy lifting, strenuous exercise and soaking the area (such as swimming) for a day or two.
• If you had sedation, do not drive, sign legal documents or drink alcohol for the rest of the day, and have someone with you.
• Check the site for increasing bleeding, swelling, redness or discharge.
• Keep any follow-up appointment to discuss your results.
• Save the clinic or ward contact number in case you have problems afterwards.

• List of your medicines, especially blood thinners, ready to show the team
• Someone to take you home if sedation is planned
• Loose, comfortable clothing for the appointment
• Simple pain relief such as paracetamol at home
• A clear note of when and how you will get results
• The clinic or ward contact number saved

Scars and how they heal

There is no surgical cut and no stitches, so there is no surgical scar. The marrow is reached through a single needle puncture in the skin over the back of the hip, which is numbed with local anaesthetic first. Afterwards you may have a small bruise and a pinpoint mark that fades over days to weeks. Firm pressure is applied at the end to limit bruising.

⚠ Get urgent help if…

• Bleeding that soaks through the dressing or will not stop with firm pressure
• A swelling at the site that keeps getting bigger
• Increasing redness, heat, swelling or discharge (signs of infection)
• A high temperature or feeling generally unwell in the days after
• Severe or worsening pain that is not eased by simple pain relief
• New numbness, weakness or tingling in the leg on that side
• Feeling faint, breathless or having a racing heartbeat

Who to contact: your clinician, clinic or test provider first (keep their number to hand). For urgent advice when you can't reach them, call NHS 111. In an emergency, call 999.

General guidance — it doesn't replace the specific advice your specialist gives you.

Results & realistic expectations

Some results, such as the simple appearance of the marrow cells, may be available within a few days. The full report — which can include how the cells look in detail, genetic tests and special stains — often takes one to two weeks, and sometimes longer for complex tests. Your specialist will usually go through the results with you and explain what they mean.

A normal or reassuring result is helpful, but no single test rules out every condition. Sometimes the sample is not enough (a 'dry tap' or inadequate core) and the test needs repeating, or other tests are needed alongside it before anything is confirmed.

A bone marrow result describes your marrow at the time the sample was taken. In a changing condition, or to check how treatment is working, the test may need to be repeated. Your specialist will explain whether and when a repeat might be needed.

Related tests, treatments or support

Bone marrow tests are usually done alongside blood tests, scans (such as CT or PET-CT) and sometimes a lymph node biopsy, depending on what is being investigated. Marrow may also be sent for genetic and specialist laboratory tests at the same sitting, so a single procedure can answer several questions.

Follow-up & long-term care

You will usually be given a follow-up appointment or a clear plan for how your results will be shared, whether in clinic, by phone or by letter. Make sure you know who to contact if you do not hear back when expected, and report any problems at the puncture site straight away.

Repeat, follow-on and what comes next

• Occasionally the liquid marrow cannot be drawn up ('dry tap') or the core sample is too small, so the test may need repeating.
• Sometimes results are inconclusive and further or repeat sampling is needed before a diagnosis is confirmed.
• Repeat tests may be planned to monitor a condition or check how treatment is working.

Ask what happens if the result is unclear or needs repeating, and what is included if further tests or follow-up are needed.

What good aftercare looks like

• Clear written advice on caring for the site and what counts as a warning sign.
• A named contact route for problems such as bleeding, swelling or signs of infection.
• A clear plan for when and how results will be shared, and who explains them.
• Sensible pain-relief advice and guidance on returning to normal activity.
• If sedation is used, written rules on driving, alcohol and being accompanied home.

What affects the cost

Costs vary a great deal between people and providers, and we don't publish prices. What matters is understanding what drives the cost and making sure your quote is complete. The main things that affect it:

• The specialist (haematologist) who performs the test and reports the findings
• The clinic or day-unit facility fee
• Whether light sedation or extra monitoring is used
• Laboratory analysis, including special stains and genetic tests, which can vary a lot
• Reporting by the laboratory and a specialist pathologist
• A follow-up appointment to discuss the results
• Whether repeat sampling is needed if the first sample is inadequate

• The specialist's fee for performing and reporting the test
• The facility or day-unit fee
• Sedation and monitoring, if you choose or need it
• Which laboratory and genetic tests are included, and which are charged separately
• The cost of a follow-up appointment to discuss results
• What happens, and what it costs, if the sample is inadequate and needs repeating
• The cancellation policy and what is covered if a complication occurs

On the NHS? A bone marrow test is widely available on the NHS when a blood specialist decides it is needed; private access is mainly for speed, choice of specialist or convenience, and the test itself is the same.

You're entitled to your total cost in writing — including reports, follow-up and what happens if the result is inconclusive — before you decide.

Consent traps and marketing red flags

These are not small details. They are often where patients lose choice, time to reflect, or realistic expectations.

Choosing a specialist safely

• Check the specialist is on the GMC Specialist Register for this area.
• Make sure they work at a CQC-registered service, and look for membership of the relevant Royal College or professional body.
• You're entitled to time to consider and to have your questions answered before you agree — the specialist who looks after you should explain it, not a salesperson.
• Be wary of pressure: time-limited offers or deposits taken before you've had time to think are red flags, not bargains.
• You're entitled to your total cost in writing — including any follow-up — before you decide.

How Vuemedics verifies every consultant →

Take this to your consultation. A good specialist will welcome every one of these.

• What are you hoping this test will show, and how will the result change my care?
• Will you take both the liquid sample and the solid core, and are any genetic tests being sent?
• Do any of my medicines, especially blood thinners, need checking or stopping first?
• What pain relief or sedation can I have, and will I be able to drive home?
• When and how will I get my results, and who do I contact if I do not hear?
• What happens if the result is normal, abnormal or unclear?
• Are you on the GMC Specialist Register for this area, and which Royal College or professional body are you a member of?
• Will you be the specialist who carries out my procedure, and who looks after me afterwards?
• What are the risks for someone like me, and how often do your own patients have a problem or need it repeated or redone?
• What does a realistic result look like — and what can this procedure not achieve?
• What are my options, including waiting, doing nothing for now, or choosing a different approach?
• Can I have written information, results and aftercare instructions in a format I can use, including any accessibility or communication support I need?
• What is the total cost in writing, including any follow-ups, and how much time do I have to decide?

Find a verified specialist for bone marrow test

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How we made this page

Medically reviewed by a GMC-registered consultant. Written in plain English, checked against NHS, NICE, GMC and relevant Royal College / specialist-society guidance, and kept under review. No clinic paid to appear on this page, and we publish no pricing. This is general information to help you prepare — it is not a substitute for advice from your own clinician. How we review our guides →

Source hierarchy: UK regulator and NHS/NICE guidance first, then relevant Royal College or specialist-society guidance, then peer-reviewed evidence for procedure-specific figures where available.

Sources & standards: NHS — Von Willebrand disease (referral to a haematologist) Cambridge University Hospitals NHS — Bone marrow aspiration and trephine biopsy University College London Hospitals NHS — Having a bone marrow biopsy Bone marrow biopsy morbidity: review of 2003 (BSH survey) — PubMed Bone marrow biopsy morbidity and mortality (BSH survey) — PubMed Bone marrow biopsy in thrombocytopenic or anticoagulated patients — British Journal of Haematology

Reviews reflect patients' experience of care, not clinical outcomes. For procedure volumes and outcome data see PHIN.

Last medically reviewed 2026-09-21. Spotted something wrong or out of date? Report an error in this guide.