I fall all the time. So, I have pretty much constant bruises in varying shades of healing all along my arms, legs and trunk of my body. I'm fortunate, in that I fall enough that I am very good at it and that means most of my bruises are generally covered up by my clothes.

Mayo Clinic told me I would be in a wheelchair full-time by the time I was 50. So far, it is eight years past that and I can still manage with a walker or cane or even just grabbing walls and doorways to take a few steps. Probably in my case, because I have kept pushing myself to keep the few "steps" that I have.

Which means that when I fell in a hotel room and gave myself a concussion (slipped on a pool of oily cleaner that had been left by the housekeeper on the floor of the bathroom and whacked my head against the side of the doorway), I ended up in the emergency room and the bruises that were uncovered (from previous falls) were pretty impressive.
Did you know that if you fall sideways into a doorknob the bruise that forms looks exactly like someone hit you in that spot with a fist?
They asked my spouse to leave, but since he and I had discussed this possibility previously, he refused and told them to ask me about the bruises. I told them they were all self-inflicted and they didn't believe me.
Since my family physician had told me that this might happen if I ever ended up in an emergency room other than the one at the local hospital, he had given me his work, home and cell phone numbers to carry with me. So I told them to give me my purse and I would give them phone numbers so that they could contact my personal physician with any questions that they might have about my bruises.
Which immediately appeared to alleviate their concerns, as they moved on to treating me instead of believing I was being abused.
I've had busy-body people approach me about any visible bruises (more often when it is warm than when I am bundled up in the winter) and I handle it by laughing and telling them that I manage to bruise myself up all by myself. Since when I am out and about, I am in my wheelchair, that does seem to stop people from arguing with me. If they did argue, I would just end the conversation and move away from them.