If you have a blister, avoid popping it yourself. Blisters develop to protect damaged skin and help it heal, so popping a blister open can cause an infection or slow down the healing process. Instead of popping a blister, cover it with a soft plaster or dressing if it looks likely to burst.
Friction blisters tend to look like a clear bubble on the skin. Sometimes a small blood vessel will bleed into the bubble, making it appear red instead of clear.
If a blister becomes infected, it may look cloudy and filled with pus.
Blisters can form if you have a burn that involves a deeper layer of the skin, called the dermis. These burns can be superficial or deep dermal burns. Superficial dermal burns can take up to 14 days to heal, while deep dermal burns may take longer to heal.
A fever blister is also known as a cold sore. It is caused by a virus called herpes simplex that most people catch from close contact with someone who has a cold sore.
Once you have the virus, it stays in your skin for the rest of your life. Sometimes it is dormant (inactive), but the virus can become active from time to time, causing a cold sore on your lip.
It is not clear what causes the inactive virus to become active, but certain factors can trigger a cold sore. These factors include having another illness, sunshine, or periods or stress.
Blood blisters are pockets of blood-filled fluid that develop when the upper skin layers separate and the space between them fills with fluid. They are usually caused by friction and pressure on a body part.
Blood blisters, like clear friction blisters, form to protect damaged skin while it heals. They are filled with blood because sometimes a small blood vessel gets damaged and bleeds into the bubble while the blister is forming.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.