Blisters
Blisters are fluid filled swellings that form within or just under your skin. The clear fluid in the blister is called serum. Blisters occur when this fluid leaks into the skin, forming a raised bump just under the outer layer of skin (the epidermis).
If the skin is very tightly pinched or squeezed, a blood blister may form. This happens when the impact on the skin is strong enough to cause a small blood vessel to rupture. Small blood vessels are located close to the surface of the skin, and a rupture allows blood to leak into the tear between the layers of skin.
Blisters are usually the result of repeated friction, such as shoes that rub, or from heat injury, such as sunburn.
Blisters commonly occur on the hands and feet, as these areas of the body often rub against shoes or equipment that is held in the hand. Blisters form more easily on moist skin than on dry or soaked skin, and are more common in warm conditions.
Sometimes, the skin blisters when it comes in contact with chemical substances or cosmetics. This is known as contact dermatitis.
There are also a number of medical conditions that cause blisters to appear on different parts of the body. This type of blister is usually filled with pus rather than clear fluid.
Most blisters heal naturally and do not require any treatment.
Try to keep blisters intact to avoid infection. Unbroken skin over a blister provides a natural barrier to infection. Never pierce the blister with a needle, but allow the blister to break on its own.
When the blister bursts, you should cover the area with a dry, sterile dressing to protect it from infection until it heals. Blood blisters should also be left to heal of their own accord. They are often painful, and you may need to apply a cold pack straight after the initial injury. As with normal blisters, it is important to keep the area clean and dry, and protect it with a sterile dressing to prevent infection.
You should consult your doctor if blisters become infected, recur frequently, form in unusual locations, or are very painful. Signs of infection include pus draining from the blister, very red or warm skin around the blister, and red streaks leading away from the blister. Your GP may prescribe antibiotics to clear up the infection.
You should also see your GP if the blisters are caused by contact with chemical substances.
