What are cold sores?

Cold sores are red, fluid-filled blisters that form near the mouth or on other areas of the face. In rare cases, cold sores may appear on the fingers, nose, or inside the mouth. They’re usually clumped together in patches. Cold sores may persist for two weeks or longer.

A common virus called herpes simplex causes cold sores. They can spread from person to person through close contact, such as kissing. The sores are contagious even when they’re not visible.

There’s no cure for cold sores, and they may return without warning. Certain medications can be used to treat cold sores and prevent them from coming back.



Visible cold sores are contagious, but they may be spread even when they can’t be seen. You can get the herpes simplex virus by coming in contact with people with the herpes simplex virus. This may happen through kissing, sharing cosmetics, or sharing food. Oral sex may spread both cold sores and genital herpes.


Once you get the herpes simplex virus, it can’t be cured but it can be managed. Once the sores have healed, the virus remains dormant in your body. This means that new sores can appear at any time when the virus reactivates.

Some people with the virus report more frequent outbreaks when their immune systems are weak, such as during illness or times of stress.

You may notice a tingling or burning sensation on your lips or face several days before a cold sore develops. This is the best time to start treatment.

Once the sore forms, you’ll see a raised, red blister full of fluid. It will usually be painful and tender to the touch. There may be more than one sore present.



You should call your doctor immediately if you develop any eye symptoms during a cold sore outbreak. The herpes simplex virus can lead to permanent vision loss when not treated promptly.

A cold sore goes through five stages:

  • Stage 2: Fluid-filled blisters appear.



The initial contraction of herpes simplex can cause more severe symptoms and complications, as your body hasn’t built up a defense to the virus yet. Complications are rare, but can occur, especially in young children. Call your doctor immediately if you’re experiencing any of the following symptoms:

Complications are more likely to occur in people who have eczema or a condition that weakens their immune system, such as cancer or AIDS. If you do have any of these conditions, contact your doctor if you think you’ve contracted the herpes simplex virus.

There’s no cure for cold sores, but some people with the herpes simplex virus rarely have outbreaks. When cold sores do develop, there are several ways to treat them.

Ointments and creams

When cold sores become bothersome, you may be able to control pain and promote healing with antiviral ointments, such as penciclovir (Denavir). Ointments tend to be most effective if they’re applied as soon as first signs of a sore appear. They will need to be applied four to five times per day for four to five days.

Docosanol (Abreva) is another treatment option. It’s an over-the-counter cream that can shorten an outbreak by anywhere from a few hours to a day. The cream must be applied several times per day.


Cold sores can also be treated with oral antiviral medications, such as acyclovir (Zovirax), valacyclovir (Valtrex), and famciclovir (Famvir). These drugs are available by prescription only.

Your doctor may instruct you to take antiviral medications regularly if you’re experiencing complications with cold sores or if your outbreaks are frequent.

Home remedies

Symptoms may be eased by applying ice or washcloths soaked in cold water over the sores. Alternative treatments for cold sores include using lip balm containing lemon extract.

Taking lysine supplements on a regular basis is associated with less frequent outbreaks for some people.

Aloe vera, the cooling gel found inside the leaves of the aloe plant, may bring cold sore relief. Apply aloe vera gel or aloe vera lip balm to a cold sore three times a day.

A petroleum jelly such as Vaseline won’t necessarily heal a cold sore, but it may ease discomfort. The jelly helps prevent cracking. It also serves as a protective barrier against outside irritants.

Witch hazel is a natural astringent that may help dry out and heal cold sores, but it can sting with application. Scientists in one study demonstrated that witch hazel has antiviral properties that may inhibit the spread of cold sores. Even so, the verdict is still out on whether cold sores heal faster if they’re kept moist or dry.

Always apply home remedies, creams, gels, or ointments to cold sores using a clean cotton swab or cotton ball.

Canker sores and cold sores both cause pain and discomfort, but that’s where their similarities end. Canker sores are ulcers that occur on the inside of the mouth, tongue, throat, and cheeks. They’re usually flat lesions. They’re not contagious and are not caused by the herpes simplex virus.

Cold sores are usually found on the lips and outside the mouth. They’re highly contagious. Cold sores are raised and have a “bubbly” appearance.

To prevent spreading cold sores to other people, you should wash your hands often and avoid skin contact with others. Make sure you don’t share items that touch your mouth, such as lip balm and food utensils, with other people during an outbreak.

You can help prevent the reactivation of the cold sore virus by learning your triggers and taking steps to prevent them. Some prevention tips include:

  • If you get cold sores when you’re in the sun, apply a zinc oxide lip balm before soaking up some rays.
  • If a cold sore pops up each time you’re stressed, practice stress management techniques such as meditation and journaling.
  • Avoid kissing anyone who has a cold sore, and do not perform oral sex on anyone who has active genital herpes.