Fever Blisters, Herpes Simplex

Herpes simplex is a virus. This virus causes fever blisters or cold sores. Fever blisters are small sores on the lips, gums, or roof of the mouth. People often get infected with this herpes virus but do not have any symptoms. The blisters may break out when a person is:

  • Tired.

  • Under stress.

  • Suffering from another infection (such as a cold).

  • Exposed to sunlight.

The blisters usually heal within 1 week. The virus can be easily passed to other people and to other parts of the body, such as the eyes and sex organs.


  • Only take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver. Do not use aspirin.

  • Do not touch the blisters or pick the scabs. Wash your hands often. Do not touch your eyes without washing your hands first.

  • Avoid close contact with other people, especially kissing, until blisters heal.

  • Hot, cold, or salty foods may hurt your mouth. Use a straw to drink. Eating a well-balanced diet will help healing.


  • Your eye feels irritated, painful, or you feel like you have something in your eye.

  • You develop a fever, feel achy, or see pus instead of clear fluid in the sores. These are signs of a bacterial infection.

  • You get blisters on your genitals.

  • You develop new, unexplained symptoms.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.