Good morning @bjd0501 There are a number of issues which can interfere with the body’s ability to produce platelets…anything from certain vitamin deficiencies, viral infections, anemia to more serious blood conditions. So, for answers, your doctor wants to get to the heart of the blood manufacturing site which is your bone marrow

Samples are taken of the bone marrow itself, along with an aspiration of peripheral blood. The analysis of these samples provides an in-depth look at the marrow’s overall health and its ability to healthy blood products; In your case, platelets.

The biopsy sounds much worse than it is. I’m not sure where you’re having this done, but some larger hospitals will offer a sedated experience where you’ll be asleep for about 15 minutes, much like a colonoscopy. If this isn’t available, you’ll have a local anesthetic injected into the area.

The samples are taking from an area on your back upper hip bone. If you feel along your back, you’ll notice the two large dimples on either side just above your biscuits. It will be around that area where the sample is extracted.

From my experience with 13 of these, you don’t have to remove your clothing. But you’ll want to wear loose fitting pants; elastic waist band is great.
You’ll be lying on one side or the other and your pants will be pulled down enough to expose that site. A drape will be over you with only the little window area open for the procedure.

The doctor will have you roll a little forward. Don’t worry, the nurses will be guiding you and this all goes fairly quickly. They’ll be talking you through everything. So the more you can relax, the easier this will be. It can feel uncomfortable though it’s more of an intense pressure than pain. When the doctor is finished with the procedure you’ll have a padded bandage placed over to maintain pressure for 24 hours. After a day you can resume taking showers and normal activities. The area might be tender for a couple days or sometimes a couple weeks.
There are many factors to the testing of the samples so it takes a week or so before results are given to your doctor.

Here’s a tutorial from Mayo Clinic that might be helpful. https://www.mayoclinic.org/tests-procedures/bone-marrow-biopsy/about/pac-20393117

Are you having this done in the doctor’s office or clinic?