A blister is an area of raised skin that appears to have a watery liquid inside. Chafing is usually caused by any activity that requires skin to repeatedly rub against another area of skin or article of clothing. Moisture can worsen chafing. The most common symptom of chafing is a painful stinging or burning sensation.
Blisters are caused by friction (rubbing), pressure or a burn. Your body responds to the friction by producing lymph fluid. As your outer layer of skin separates from the inner layers the space between them fills with fluid and the fluid builds up beneath the part of the skin being rubbed, causing pressure and pain. A single blister is often caused by:
Friction: Blisters can develop when a surface rubs against unprotected skin. This includes:
Burns: Blisters can develop when your skin is exposed to open flames, steam, or contact with a hot surface or excessive exposure to the sun (sunburn).
Other causes of blisters include contact with irritants (chemicals, plants or toxins); drug reactions, autoimmune diseases and infection. If you have multiple blisters or severe burning you should see your doctor immediately.
You can treat minor blisters at home by protecting the blistered skin from further irritation or rubbing, keeping the skin hydrated, and guarding the skin against sweat and other irritants. This is important as "de-roofing" (taking the top part of the blister off) increases your risk of infection and can increase pain. While your blister heals, try to avoid rubbing or putting pressure on the area.
Mild chafing can often be treated by keeping the area properly hydrated (with appropriate lubricants) and protected from sweat or other irritating moisture.