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What is Oral Herpes?

C. Martin
C. Martin

Oral herpes is a mouth infection that is caused by a virus called herpes simplex. The symptoms appear in the form of lip sores, often colloquially referred to as cold sores, and, in some cases, sores on the mucous membranes of the oral cavity. These mouth sores are usually blisters filled with fluid, which eventually burst.

The herpes virus is extremely common; medical professionals state that the percentage of people who have experienced some form of herpes infection by the time they reach adulthood is close to 100 %. There are in fact two different types of the herpes simplex virus (HSV), called HSV-1 and HSV-2 respectively. HSV-1 is by far the more common of the two viruses, but they are very similar, causing the same symptoms in the infected person. Both types of the virus can also cause the related infection, genital herpes.

Oral herpes can be transmitted through kissing.
Oral herpes can be transmitted through kissing.

In addition to the main symptoms of lip sores and oral blisters, sometimes additional symptoms are experienced during an oral herpes infection. These symptoms may include swollen gums, fever, headache, and dehydration. Young children are particularly prone to suffering from these unpleasant symptoms, and often experience significant pain in the mouth, which can make it difficult to eat.

Herpes can be spread through oral sex.
Herpes can be spread through oral sex.

Oral herpes is very infectious. It can be transmitted by kissing other skin contact, or by the sharing of items that come into contact with the mouth, such as a toothbrush or lipstick. In addition, the virus can be passed from the mouth to the genitals, or vice versa, during oral sex.

When a person becomes infected with oral herpes, the virus normally proceeds through three distinct stages. The first time a person is infected, the viruses penetrate the membranes of the mouth and begin to reproduce. This is called a primary infection, and may be accompanied by sores and other symptoms. Alternatively, it may occur without any symptoms, in which case it is called an asymptomatic infection.

Oral herpes causes sores to form on the lips and area around the mouth.
Oral herpes causes sores to form on the lips and area around the mouth.

In the second stage of the infection, the virus migrates from the mouth to the nervous tissue in the spine. Here, the virus continues to reproduce for a period, and then becomes inactive. This stage of the infection is called latency, and the infected person will typically continue to be a host to the virus on a permanent basis.

Herpes sores appear from time to time. This usually happens when the infected person becomes stressed, either physically or mentally. This stage is called recurrence, and is likely to occur repeatedly, as the virus alternates between latency and activity.

Discussion Comments


@MikeMason-- So how can we know if someone has a cold sore or an oral herpes?


@simrin-- Let me try and clarify it for you. I'm not a doctor but I read a lot about this. I still get confused about it sometimes.

HSV-1 is the virus that causes what we refer to "cold sores." This is a relative of the virus that causes genital blistering, but it's not the same. HSV-1 usually causes blisters on the lip and around the mouth when a person's immune system is weaker or during winter months. It doesn't cause blisters in the genital area and very rarely does it cause a blister inside the mouth.

HSV-2 is the virus that's transmitted sexually and causes blistering in the genital area and sometimes the mouth area. If someone has oral sex with another who carries the virus, the virus can transmit and cause blisters and lesions in the mouth. Those who carry the virus can also re-infect themselves if they have oral sex with their partner while the virus is active.

So the cold sore that you're experiencing is from HSV-1. Almost all of us have HSV-1, I personally don't think it's anything to worry about. If you experience oral blistering in addition to genital blistering, then you might have HSV-2 and oral herpes requires treatment with antiviral medications.


I'm confused, cold sores are caused by the herpes virus?! I have cold sores sometimes, does this mean I have oral herpes? I've never had genital sores.

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    • Oral herpes can be transmitted through kissing.
      By: Antonioguillem
      Oral herpes can be transmitted through kissing.
    • Herpes can be spread through oral sex.
      By: Imagery Majestic
      Herpes can be spread through oral sex.
    • Oral herpes causes sores to form on the lips and area around the mouth.
      By: Marco2811
      Oral herpes causes sores to form on the lips and area around the mouth.