Blisters On Feet

Written By: Chloe Wilson BSc(Hons) Physiotherapy
Reviewed By: FPE Medical Review Board

Blisters on Feet: Common causes, symptoms, treatment and prevention

Blisters on feet and toes are a common problem and cause of foot pain.  A foot blister is a small, fluid filled bubble-like pocket that develops on the upper layers of skin.

Blisters can vary in size and depth depending on the cause.

In most cases, blisters are caused by friction, but they can also occur due to things such as infection, burns and chemical exposure.  They usually contain clear fluid known as plasma, but can sometime contain blood or pus.

Here, we will look at how they develop, the different types of blisters and common causes of each and then we'll look at the best treatment options and prevention strategies for blisters on toes and feet. 

How Do Foot Blisters Develop?

Blisters on feet develop when the skin on part of the foot is damaged, most commonly from friction.  In an attempt to protect itself from further damage, fluid collects under the injured skin to provide cushioning and allow healing. This fluid forms a small pocket, known as a blister.

They can occur anywhere on the body, but hand and foot blisters are the most common. Blisters are one of the most common types of foot rash

Types of Foot Blister

Blisters on feet typically fall into one of three groups based on how they appear:

  • Clear Blisters: In most cases, blisters on feet are filled with clear fluid, known as serum aka plasma.  Serum is one of the components found in blood, alongside red blood cells and clotting factor.  It is made up of proteins, antibodies, hormones, antigens and electrolytes. 

  • Blood Blisters: Sometimes, blisters may appear red or black which indicates that they contain blood.  This happens when some of the small blood vessels are damaged as well as the skin. 

  • Infected Blisters: If blisters on feet become infected, pus forms and collects giving them a whitish or yellow tinge.

What Causes Blisters On Feet?

There are a number of possible causes for blisters on feet. The most common are:

1. Friction Blisters

The most common cause of blisters on toes and feet is friction. They tend to develop when walking or running long distances or when wearing new or poor-fitting shoes (too tight or too loose) which rubs on the skin, causing fluid to accumulate under the top layer of skin.  

Burst friction blister

Blisters on toes are more common when the skin is moist and warm rather than when it is dry or soaked.  This is one of the reasons people are often caught out – they may not be walking/running any further than normal but if they are going faster, the weather is warmer or wetter or their footwear is warmer material, their feet may perspire more, increasing the likelihood of blisters on feet. 

There is often a misconception that blisters on toes develop from repetitive friction, however, it actually tends to be sudden, brief, intense friction or rubbing on the skin that causes blisters on feet. Prolonged, repetitive, less intense friction on the skin is more likely to result in foot corns or calluses

2. Foot Blisters From Excessive Cold

Frostbite blister on foot, 3 days after exposure

Tissue damage from frostbite can also cause blisters on feet.  When we are exposed to temperatures below freezing, blood vessels contract pushing blood away from our extremities, particularly the hands and feet in an attempt to keep us warm.  This can lead to skin tissue damage and even death. 

Frostbite can be categorized in four stages, depending on severity, and blisters on toes are usually associated with second-degree frost bite.

3. Foot Blisters From Excessive Heat

Blisters can also develop in response to intense heat due to:

  • Burns: First degree burns will often blister after a couple of days as they are healing.  Second-degree burns usually blister immediately

  • Sunburn: Excessive exposure to UV light leads to sunburn which can result in painful blistering of the skin

4. Blisters From Medical Conditions

There are also a number of medical conditions which can cause blistering of the skin such as chicken pox, shingles, herpes, impetigo, cold sores, scabies and some forms of eczema.  

5. Chemical Blistering

Blisters can develop due to an allergic reaction to various chemicals

Skin may also develop blistering when in contact with certain chemicals, solvents, detergents or cosmetics. 

Chemical blisters will vary in size and severity depending on the severity of the allergic reaction.

It is always advisable to wear gloves when using any chemicals to prevent skin irritation and blistering.

How To Get Rid of Blisters On Feet

Most blisters on toes and feet will heal naturally, without requiring medical care.  When possible, you want to avoid breaking them to reduce the risk of infection.  Always wash your hands or wear gloves before touching a blister to reduce the risk of infection.

1. Treating Unburst Blisters

If possible, avoid bursting blisters.  Leaving the skin intact provides a natural barrier, reducing the risk of infection.  As it heals, the skin will naturally harden and fall off.  Ideally, leave blisters on feet uncovered and avoid wearing any shoes that rub. 

If necessary, you can cover a foot blister with either a plaster or gauze pad depending on their size or try using a product such as a Compeed dressing pad to prevent further friction on the area.

2. Treating Burst Blisters

Burst blister on toe.  Avoid removing the dead skin when possible to help reduce the risk of infection

Most large blisters on toes will break on their own. Don’t be tempted to remove the broken skin.

Instead, allow the fluid to drain and then cover the area with a sterile dressing which should be changed daily until it is fully healed.

3. Draining Blisters

If a large blister is causing considerable discomfort, you may need to drain it.

Wash your hands before you start and use a clean, sterile needle to make small puncture holes around the edge of the blister, rather than the centre.

Gently press over the area so the fluid drains out, then wash the area, pat dry and cover with clean gauze. Change the dressing daily.

4. Products That Can Help

Compeed is a specially designed dressing forfoot blisters

There are a number of products that can help in treating foot blisters such as special dressings and gauze. One of the most popular is Compeed blister pads.  

5. Footwear

If your blisters on feet are the result of wearing new shoes, avoid wearing them again until the foot is fully healed.  Then break the shoes in by wearing them for short periods until they soften.

What Else Can Help?

Blisters on feet are just one problem that affects the feet and toes, there are many other causes of foot rashes.  You can find out more about other common problems in the causes of foot pain section.

Alternatively, if you want help working out what is causing your pain, visit the foot pain diagnosis section.

Page Last Updated: 10/01/22
Next Review Due: 10/01/24

Related Articles

Common causes of toe joint pain

Toe Pain
May 17, 2022

Common Foot Pain Symptoms and what they mean

Common Symptoms
January 27, 2023

Swollen Feet & Ankles: Common causes, symptoms, diagnosis and treatment options

Swollen Feet
September 28, 2022