What Is A Blister?

A blister is a small fluid-filled bubble that forms just under the outer layer of the skin. The fluid serves as a natural cushion to protect the tissue underneath from friction and irritation.  Most often, the fluid inside the blister is serum; however sometimes the blister may be filled with blood (“blood blister”) or pus (if the blister gets infected).  

Most blisters on your feet are friction blisters, which are often caused by excessive rubbing against your shoes and socks.

Foot blisters are very common and not usually cause for concern; however they can be quite bothersome.  Many go away on their own once the source of irritation is removed.  If a blister pops, it can be quite painful. A popped blister also removes the protective fluid barrier, which can lead to infection or further skin irritation.

What Are Symptoms Of A Blister?

Common symptoms of a foot blister include:

• A circular shaped bubble (unpopped blister) or raw sore (popped blister), most commonly occurring on the toes or heels
• Clear or bloody fluid by the affected area
• Stinging, pain or redness by the affected area

Why Do I Get Blisters?

A blister is formed by the body’s response to skin damage:  In order to protect the tissue underneath the skin, the body builds a fluid-filled cushion (the blister) to protect it from whatever is causing the skin damage.  The fluid inside the blister is called “serum” and is often clear.  If the fluid is bloody, it is called a “blood blister”.  

Foot blisters are most frequently caused by friction.  Friction blisters in the feet are typically the result of ill-fitting footwear, which causes excessive rubbing between the skin and the inside of the shoe.  Most often, foot blisters form on the toes or around the back of the ankle. They form more easily when the skin is moist and damp, i.e.: if someone has sweaty feet.  Although bothersome, friction blisters are not usually serious and often go away on their own once the friction source is removed.

Some of the less common causes of foot blisters can include:

1. Exposure to extreme temperature:  The skin can blister in response to extreme hot or cold temperatures. For example, a very bad sunburn may result in blisters.
2. Allergies (Contact Dermatitis):  These blisters are formed when the skin comes into contact with a chemical or surface that prompts an allergic reaction. Poison ivy is a common agent of contact dermatitis. 
3. Chemicals:  Some chemicals are skin irritants and prompt the skin to produce blisters.  Many of these are considered hazardous chemicals, such as mustard gas. 
4. Medical Conditions:  There are some conditions that trigger the body’s immune system to produce skin blisters.  The most common of these conditions include:

• • Chickenpox
  • Herpes
  • Dyshidrosis

How Do I Treat A Blister On My Foot?

For most people, blisters heal naturally on their own within a few days (so long as they’re left alone and not aggravated).  Do not play with or pop a blister.  

For friction-related foot blisters, the first step is to avoid the footwear that caused the blister in the first place (as well as any other footwear that will rub up against the area):  The continued rubbing action will aggravate the blister.  

To avoid additional friction that may further aggravate the inflamed area, you can cover the blister with an adhesive bandage or blister pad.  Products specially designed for foot blisters are available at our Toronto foot clinic.

If your blister pops, wash the area with soap and water and then apply a bandage.  If your blister is very large or painful, you can see a doctor or foot specialist for additional treatment.  This may involve draining the blister and applying an antibacterial ointment to prevent infection. 

If you have diabetes, a simple foot blister can easily become an infected wound and lead to complications.  Individuals with diabetes must regularly examine their feet for blisters.  Continued foot care by a foot specialist is recommended.

To schedule foot care treatment for your blisters with our licensed Chiropodists (foot specialists), use our booking form or call 416-769-FEET(3338).

Our Toronto foot clinic is open Monday-Friday 9 am-6 pm, Saturdays 9 am-4 pm and Sundays from 10 am to 4 pm. You do not need a referral to become a patient at our Foot clinic.

What Causes Blisters?

Certain risk factors may increase your chances of developing a blister on your foot:

• Wearing shoes that are too tight or too loose, that persistently rub against the skin
• Wearing shoes with prominent seams:  These seams often protrude and then persistently rub against the skin.
• Sweaty feet:  The outermost layer of our skin is most vulnerable and sensitive to friction when it is wet.

How Do I Prevent Blisters On My Feet?

Here are various foot care solutions you can do to prevent blisters on your feet:

• Wear shoes that fit properly
• Gradually break in new shoes
• Wear wool or other moisture-wicking socks during exercise
• Sprinkle baby powder in your socks if you get friction blisters due to sweaty feet
• If your feet rub along a specific area of your shoe, wearing an insole may reposition the foot and reduce friction
• Properly lace your shoes to prevent heel slippage
• Protect blister-prone areas with soft materials, such as moleskin

*Moisture control socks, insoles, foot powders, and blister bandages are available in our Toronto foot clinic. We are open Monday – Friday from 9 am – 6 pm, Saturday from 9 am – 4 pm and Sunday from 10 am to 4 pm.