What are cold sores?

Cold sores, also known as fever blisters or herpes labialis, are painful, blister-like sores on or around the mouth caused by the herpes simplex virus (also known as HSV). Typically, they form on the lip, but they may also form on the chin, nose or cheeks, or inside the mouth. Often, a tingling, itching or uncomfortable sensation occurs in the area before blistering occurs. A solitary blister or clusters of small, painful blisters emerge that ultimately burst, scab over, and then heal. Once you have had an HSV infection, the virus resides in your body and can cause repeated outbreaks of cold sores in the same general location.

There are two types of HSV, type 1 and type 2. Generally, type 1 is associated with cold sores and type 2 with genital herpes; however, either type may cause sores in either the oral or genital region. HSV is very contagious and is spread by skin-to-skin contact, such as kissing or sexual contact, including oral-genital contact. HSV type 1 is very common. It is estimated that more than half of the people in the United States have been infected by the time they reach their 20s (Source: NIH).

Many people who have an oral HSV infection do not develop symptoms and may not even realize they are infected, while others develop large clusters of painful blisters. Currently, HSV infections are not curable, but self-care and medications can help relieve the symptoms of cold sores and decrease the number of outbreaks. To help reduce the spread of the infection, refrain from oral and oral-genital contact when symptoms are present.

Cold sore symptoms may be more difficult to control in people with a suppressed immune system, such as those who have AIDS (acquired immunodeficiency syndrome), are undergoing cancer treatment, or have had an organ transplant. Seek prompt medical careif you are unable to eat or drink due to the cold sores, if you have a suppressed immune system, or if the cold sores are near your eyes. Also seek prompt care for severely painful sores, sores that last more than two weeks, or frequent recurrences.


What are the symptoms of cold sores?

Symptoms of cold sores tend to be localized to the area of the outbreak and often follow a specific course, although the intensity varies from individual to individual.

Common symptoms of cold sores

Most cold sore symptoms are limited to the area of the outbreak and include:

  • Blisters on the lip, nose, chin or cheeks, or inside the mouth
  • Read more about cold soressymptoms


What causes cold sores?

Cold sores are caused by the herpes simplex virus (HSV). Two types of the virus exist, type 1 and type 2. Cold sores are most commonly caused by HSV type 1, but they can also be caused by type 2. Herpes infections are very contagious and are spread by skin-to-skin contact. It is possible to spread the virus even if cold sores are not present, and not all people who have been infected with it wi... Read more about cold sorescauses


How are cold sores treated?

Currently, cold sores cannot be cured; once a person is infected with herpes simplex virus, it does not go away. People who develop cold sores may continue to have periodic outbreaks. Between outbreaks, the virus resides in the nerves of the face. When the virus is reactivated, another outbreak of cold sores occurs, typically in the same place as the original cold sores.

The goal ... Read more about cold sorestreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Aug 9, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Mouth, Teeth and Oral Health