Bedsores may look like discoloration on the skin, a blister with fluid, or a crater-like ulcer, depending on the stage. In severe cases, bedsores can show muscle and look yellow or crusty due to dead tissue, notes Mayo Clinic. Bedsores are in one of four categories, depending on their severity.
In stage one, the skin is not broken and appears red or shows discoloration, according to Mayo Clinic. In stage two, there is damage to the outer layer of skin, the cut is shallow, and it looks pink or red. In stage three, there is a deep wound that shows fat and may contain dead tissue. In stage four, the wound goes beyond the skin. Extremely severe bedsores are unstageable and look black, brown or yellow.