Cold Sores: Everything You Need to Know

Cold sores are small, fluid-filled blisters that typically form on the lips and often occur in groupings. As they evolve, they form a scab that lasts several days. Also called fever blisters, cold sores generally heal in two to three weeks and don’t cause scarring.

In some cases, cold sores can form inside the mouth or on the nose or fingers.

What Triggers a Cold Sore?

Cold sores are caused by a highly contagious type of herpes simplex virus called herpes simplex virus type 1 (HSV-1). This virus is common, and many people are first exposed to it as children. Having a cold sore caused by HSV-1 doesn’t mean you have a sexually transmitted disease (STD).

Less commonly, cold sores can be caused by HSV-2. This is the virus that typically causes genital herpes, which is an STD.

Herpes viruses remain dormant (meaning inactive) in your body after you’re exposed to them, living in certain nerve cells until they’re “triggered” later. Several conditions can trigger a cold sore, including:

• Fever from an illness like a cold or flu
• Emotional or physical stress
• Hormonal changes that occur during menstruation or pregnancy
• Sunburn
• Dry or cracked lips
• Exposure to very cold or hot temperatures
• Fatigue

A triggering condition in one person may not be a trigger for another. And some people who have the HSV-1 or HSV-2 virus in their body may never develop a cold sore. 

Contact your doctor promptly if you experience any eye symptoms when you have a cold sore. The virus that causes cold sores can lead to permanent vision loss if not treated right away.

How Long Are Cold Sores Contagious?

Cold sores are contagious until they’ve completely resolved, which typically takes about two weeks. It’s important to note that cold sores are highly contagious and can be spread even when they’re not visible. 

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Can I Kiss Someone When I Have a Cold Sore?

Because cold sores are very contagious, you shouldn’t kiss anyone while you have one. This includes the early stages when you feel the telltale tingling or burning sensation but haven’t developed the blisters. 

Other cold sore symptoms can include:

• Sore throat
• Painful gums
• Fever
• Headache
• Swollen lymph nodes in the neck
• Muscle aches

To keep from spreading the virus, you should also do the following when you have a cold sore:

• Avoid sharing anything that has touched your mouth, including food and drink, utensils, cosmetics, etc.
• Wash your hands frequently and thoroughly, especially after you’ve touched your lips or any part of your face.
• Avoid kissing others for approximately two weeks from the first sign of a cold sore, particularly when the fluid-filled blisters are present, but also before and after they appear.

How Can I Prevent Cold Sores or Get Rid of Them Fast?

The virus that causes cold sores can’t be cured or eliminated from the body. However, there are actions you can take to avoid getting a cold sore or help shorten the healing time if a cold sore develops. 

To prevent cold sores, learn what your triggers are and avoid them. For example, if you have had cold sores in the past following a sunburn, wear a lip balm that has a high sun protection factor (SPF) and take other steps to minimize your sun exposure. If stress causes you to develop cold sores, learn to lower your stress level. It’s also important to get plenty of sleep and eat a healthy diet. And you should avoid kissing someone if they have a cold sore or think they may be developing one.

If you get cold sores frequently, your doctor may prescribe an antiviral medication you can take regularly to prevent outbreaks. 

As for treatment, antiviral medications can also be used to reduce the severity of an outbreak. In addition, over-the-counter balms and ointments may help minimize cold sore symptoms and accelerate healing. Docosanol (Abreva) is one example. For best results, balms must be applied at the first sign of a cold sore and applied four or five times a day.    

Talk with a Baptist Health Physician About Cold Sores

If cold sores are a problem for you, your Baptist Health doctor can help. Use our online provider directory to find a physician if you don’t already have one. 

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