I was walking in Snowdonia this morning. We've just got home and I have found a blood-blister with a bit of swelling around it near the back of my inner thigh. There are darker patches on the blister. Where did it come from? My trousers didn't chaffe. Have I been bitten by something? Worse yet, have I been bitten by something that is still there, and the pressure of sitting in the car for several hours while driving home has pressed it under my skin?
Oh what do I doooo?!