An ingrown hair blood blister is a small, fluid-filled bump that forms when a hair grows back into the skin. These blisters can occur anywhere on the body, but they are most common in areas that are prone to shaving, such as the face, legs, and underarms. Ingrown hair blood blisters can be painful and irritating, and they can sometimes lead to infection.
Ingrown hair blood blisters are a common problem, but there are a number of things that can be done to prevent them. These include shaving in the direction of hair growth, using a sharp razor, and avoiding shaving too often. If an ingrown hair blood blister does develop, there are a number of treatments that can be used to relieve the pain and irritation. These include applying a warm compress, using an over-the-counter pain reliever, or seeing a doctor.