A blister is a small pocket of fluid (usually clear serum, but can be blood or pus) that forms under the top layer of skin. They are typically round or oval and can vary in size. Blisters form as a protective mechanism by the body to cushion and heal damaged skin underneath, often caused by friction, burns, or reactions to certain substances.
Generally, it's best not to pop a blister. The skin over the blister acts as a natural barrier against infection. If you pop it, you break this barrier, increasing the risk of bacteria entering and causing an infection. It's usually better to leave the blister intact and let it heal naturally. If a blister is very large, painful, or in an awkward place, and you feel you must drain it, do so carefully using a sterilised needle and then keep the area clean and covered.
Preventing blisters often involves reducing friction. For feet, ensure you wear well-fitting shoes and socks, and consider moisture-wicking materials. You can also use protective pads, tapes, or creams in areas prone to rubbing. For hands, wear gloves when doing activities that cause friction. For burns, immediate cooling can help reduce blister formation. Keeping skin moisturised can also help maintain its integrity.
You should see a doctor or pharmacist if a blister becomes very painful, swollen, red, or starts producing pus, as these are signs of infection. Also seek advice if you have a fever or red streaks extending from the blister. People with certain conditions, like diabetes or poor circulation, should seek professional medical advice for any blister, as they are at higher risk of complications.