Ive woken up with a red lump on the back of my thigh, it has a dark centre (almost looking as if blood is trapped under the skin) and is sore to touch...I was wondering if anyone could tell me what this could be and whether I need to go to the doctors or if it will disappear on its own.
Hi, This could have been caused by an insect bite. As you describe it as painful and red, I think it may be infected and there is a risk you may develop cellulitis. Therefore, I suggest you go to the ED for assessment and possible antibiotics.  Chat Doctor.