A blister is a bubble on the skin containing fluid. Blisters are usually circular in shape. The fluid that forms underneath the skin can be bloody or clear.
Injury, allergic reactions or infections can cause blisters. These include:
Blisters caused by injury or friction will appear as a localized bubble filled with either clear or bloody liquid. Blisters that are the result of another condition may appear in one area of your body or may be all over your body. Blisters may be painful or itchy. If there is a systemic cause, like an infection, you may also have whole-body symptoms such as fever, pain, or fatigue. The symptoms of a blister may look like other skin conditions. Always see your physician for a diagnosis.
Your physician can usually diagnose blisters by looking at your skin.
Blisters often heal on their own without treatment. If needed, treatment will vary, depending on the cause. Some general guidelines for first aid may include: