A blister can be isolated, or many can develop and affect several areas of the body.
Read on to find out more about the symptoms of blisters and what can cause them. This article also looks at treatments for getting rid of blisters, when to contact a doctor, and more.
The symptoms of blisters can depend on the type of blister. Some blisters, called “bullae,” are large, while others are small. Small blisters are called “vesicles.”
Blisters generally fall into three categories.
Friction blister
A friction blister is a collection of clear, colorless fluid trapped between or beneath the top layer of skin, the epidermis.
Friction blisters typically form when skin rubs against a surface, causing friction. They commonly occur on the hands and feet.
Learn more about friction and chafing.
Blood blister
A blood blister results from damage to blood vessels and tissues just under the skin. This damage causes blood and other fluids to pool and form a bump.
Blood blisters typically look red or black in appearance.
Learn more about blood blisters.
Burn blister
A burn blister, or heat blister, forms over your skin if you experience a mild to severe burn from heat or chemical exposure.
It’s important to protect a heat blister while the skin underneath heals. Bursting a burn blister can lead to infection.
There are numerous causes of blisters. Friction blisters can develop on the feet from poorly fitting shoes or on the hands from working with gardening tools.
Some people may develop blisters because of an infection or an underlying condition. Contact your doctor if you experience frequent blisters or if you develop an infection.
Injury
An injury or irritation can cause blisters. Causes include:
- chafing or friction
- insect bites
- chemical, electrical, or heat burn
- frostbite
- sunburn
Infection
You may develop blisters if you have an infection. Examples of infections that can cause blisters include:
- bacterial skin infection, such as impetigo
- varicella-zoster infection, which can cause chickenpox and shingles
- herpes simplex virus infection, which causes cold sores and genital herpes
Contact your doctor if you have an infection or notice that a blister has become infected.
Other cause
Other conditions that can cause blisters include:
- adverse drug reaction
- allergic skin reaction
- eczema
- scabies
- dermatitis herpetiformis
- pemphigus vulgaris
- porphyria cutanea tarda
- bullous pemphigoid
Treatment aims to protect the blister and prevent it from bursting. Protection allows the skin underneath the blister to heal and prevent infection.
In most cases, such as with friction blisters, the blister will heal on its own.
Keeping the blister clean will prevent infection. Keep the area covered with a soft plaster or dressing to prevent further damage. This will also reduce the risk of the blister bursting.
Contact your doctor if your blister is due to a skin condition or other health condition. They can advise on treatment based on the blister’s specific cause.
Seek medical advice if you develop a burn blister. You may need medical treatment and dressings to reduce the risk of infection.
Contact your doctor if you frequently develop unexplained blisters or if a blister does not go away.
Your doctor can order tests to identify the cause. They can also recommend treatments to alleviate symptoms and address the underlying cause.
You should also contact your doctor if:
- the blister shows signs of infection, such as heat and yellow or green pus
- you develop a fever with the blisters
- you develop more blisters
- blisters occur because of a burn, chemical burn, frostbite, or other injuries
- you have circulatory problems or a condition such as diabetes
Your doctor may make a diagnosis after a physical examination. However, if you frequently experience blisters or if your doctor suspects your blister is due to an underlying condition, they may order tests to reach a diagnosis.
Tests can depend on the type of blister and your other symptoms but may include:
- taking swabs to test for infection
- a skin biopsy
- blood tests
Your doctor can explain the tests further and answer your questions.
Depending on the cause, you may prevent blisters by taking precautions or treating the underlying condition that can cause blisters to form.
Steps you can take to reduce your risk of developing blisters include:
- wearing shoes that fit properly
- wearing socks with your shoes
- reducing friction by using talcum powder
- wearing gloves or protective clothing on vulnerable areas
- applying sunscreen with an
SPF of at least 30 Trusted Source Food and Drug Administration (FDA) Governmental authority Go to source to prevent sunburn blisters
Find out more about how to prevent foot blisters.
Learn answers to other questions about blisters.
Is it better to pop a blister or leave it be?
You should not pop a blister yourself because this can increase the risk of infection. A blister may break on its own when it is ready.
How long does a blister take to heal?
Blisters typically heal within about 1 week. Contact your doctor if you have a blister that lasts longer and does not appear to be healing.
Does ice help blisters?
An ice pack can help to alleviate pain from a blood blister. The UK’s National Health Service recommends applying an ice pack for about 10–30 minutes immediately after the injury.
How do you make blisters heal faster?
Keeping a blister covered and preventing further friction or injury can help it heal faster.
There are many blisters, including friction, blood, and burn blisters. Many will heal on their own within about 1 week. During this time, keep the blister clean and protected.
You may need medical treatment in some cases, such as blisters that occur due to a severe burn. A doctor can dress the blisters to protect them from damage.
If your doctor suspects your blisters are due to an underlying condition, they may order tests to reach a diagnosis.
Following your treatment plan may help reduce the blisters and prevent them from recurring.
Contact your doctor if you have concerns about blisters or notice signs of infection.
