There are different types of blisters that have different causes such as blisters as a symptom of a disease or blisters caused by burns. This page is about friction blisters (blisters caused by friction/rubbing) which can be common on the feet. If you have a blister that is not caused by friction you should seek advice from a healthcare professional on what has caused the blister and the best way to treat it.
A blister is bubble of fluid between the layers of the skin than forms as a result of intense friction on the skin. They usually happen when you change your activities such as wearing a new pair of shoes or taking up a new sport. The first sign of a blister is hot spot – a hot, red area that is being rubbed by shoes or socks. If the rubbing continues this develops into a blister that can be very painful. If the blister bursts it can be even more painful as the new pink skin underneath is exposed.
Blisters should not usually be burst – the roof of the blister provides protection and should not be removed. Blisters should be protected – from pain, further damage and infection - using appropriate dressings and should quite quickly heal.
What is a friction blister?
A friction blister is a bubble of fluid between the layers of the skin caused by quite intense friction (rubbing). On the feet, this friction will usually be caused by the shoes or socks/hosiery rubbing across the skin.
The skin is made up of several different layers and as it is rubbed it forces two of these layers apart - forming a pocket just under the skin surface. This pocket quickly fills up with fluid to create the typical bubble-like appearance of a blister. This bubble of fluid acts like a small cushion, protecting the skin underneath the blister from the rubbing. If the rubbing continues the blister will sometimes pop and the fluid will come out, leaving a red patch of skin that can be very sore and tender.