A bone marrow biopsy is typically only necessary in ITP to rule out other conditions or if you're not responding to standard treatments. The procedure involves local anesthesia and feels like strong pressure and brief pain as the sample is taken from your hip bone. Most people find it manageable though uncomfortable. It's a quick procedure (15-20 minutes) and any pain afterward usually responds well to over-the-counter pain medicine.

Remember: Only your doctor can determine if you need this test based on your specific situation.