Bone marrow aspiration is a procedure that involves taking a sample from the soft tissue inside your bones. Bone marrow is the spongy tissue found inside bones. It contains cells that produce white blood cells, red blood cells, and platelets inside larger bones such as the:

  • spine
  • breastbone
  • hips
  • ribs
  • skull

White blood cells help fight infection. Red blood cells carry oxygen and nutrients. Platelets enable your blood to clot.

If a complete blood count shows that the number or function of red blood cells, white blood cells, or platelets is abnormally high or low, your doctor may want to examine your bone marrow to help figure out the cause. Bone marrow aspiration is often performed with a bone marrow biopsy, which uses a different type of needle to remove tissue from your bone marrow.

Numerous conditions are associated with unhealthy bone marrow. If preliminary blood tests show low levels of white or red blood cells or platelets, your doctor may order a bone marrow aspiration. The test is used to check for disease as well as to monitor the progression or treatment of a specific disease.

Conditions and diseases related to bone marrow problems include:

  • anemia, which is a low red blood cell count
  • bone marrow diseases, such as myelofibrosis or myelodysplastic syndrome
  • blood cell conditions, such as leukopenia or polycythemia
  • cancers of the bone marrow or blood, such as leukemia or lymphoma
  • hemochromatosis, which is a genetic disorder in which iron builds in the blood
  • infection, especially chronic diseases like tuberculosis
  • storage diseases, such as amyloidosis or Gaucher’s disease

Bone marrow aspiration can also be an important test if you're having cancer treatment. It can help determine if the cancer has spread to the bones.

Bone marrow exams are safe, but all medical procedures carry some type of risk. In rare instances, the following complications are possible:

  • an allergic reaction to anesthesia
  • excessive bleeding
  • an infection
  • long-lasting discomfort

The risks are rare and most often associated with conditions that cause a weakened immune system or low platelet count. A weakened immune system can make you more prone to infection, and a low platelet count increases your risk of excessive bleeding.

You should let your doctor know about any medications you may be taking, including over-the-counter (OTC) medicines or nutritional supplements. You should also let them know about any allergies you have. Your doctor may ask you to stop taking certain medications before the procedure. But you shouldn’t stop taking any medications unless your doctor instructs you to do so.

Tell your doctor if you’re nervous about the procedure. They may give you a mild sedative to help you through the procedure.

Follow any additional instructions from your doctor before the procedure.

You’ll be asked to change into a hospital gown and lie down on your side or abdomen. Your body will be covered with a cloth so that only the area being examined is visible.

Your doctor will check your heart rate and blood pressure before the bone marrow aspiration.

Just before the procedure, you’ll be given local anesthesia to numb the area where the aspiration will take place. This is typically at the top ridge of the rear of the hipbone. Occasionally, it may be taken from the chest bone.

Your doctor will make a small incision that makes it easier for a hollow needle to go into your skin. The needle then goes into the bone. Your doctor uses a syringe on the back of needle to draw out the fluid portion of the marrow.

Immediately after the procedure, the incision will be bandaged and you’ll go into another room to rest before going home.

You may feel some slight pain for about a week after the procedure. You can typically manage it with OTC pain relievers. You’ll also have to take care of the incision wound. You should keep the wound dry for 24 hours after the procedure.

While you’re caring for your wound, your bone marrow sample will go to a laboratory for testing. Your doctor will review test results with you during a follow-up appointment.