Blisters have many causes, such as:

  • Friction or constant pressure
  • Second-degree burns
  • Infections
  • Skin irritation from:
  • Certain cancers
  • Blistering diseases—such as epidermolysis bullosa, porphyria, or pemphigus
  • Autoimmune disorders

Risk Factors

Things that may increase the risk of blisters are:

  • Wearing shoes tht do not fit well
  • Repetitive work with hand tools
  • Getting a sunburn or frostbite
  • Severe skin swelling, especially of the legs



Symptoms of a blister are:

  • A fluid-filled bump on the skin, which is often round
  • Fluid that is usually clear, but may be bloody, cloudy, or contain pus


The doctor will ask about symptoms and past health. A physical exam will be done. Blisters may be diagnosed on appearance.



A blister will often heal without treatment. Sometimes the underlying cause needs to be treated.

Treatment options are:

  • Washing the area
  • Applying over-the-counter medicine—to ease itching and discomfort
  • Applying antibiotic ointment—to prevent or treat an infection
  • Bandaging the area—to protect it


To lower the risk of a blister:

  • Wear shoes that fit properly. Always wear socks with your shoes.
  • Use gloves or protective padding when working with tools.
  • Wear a hat, protective clothing, and sunscreen when out in the sun.
  • Avoid skin contact with irritating chemicals or plants

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.