Cold sores are caused by the herpes simplex virus type 1 (HSV-1). The virus causes blisters to form around the mouth and nostrils. Cold stores have several stages during which the blisters pop and join together to form sores.
There is no cure for HSV-1. Once you contract the virus, it stays in your body for the rest of your life. Most people get herpes through physical contact with an infected person. If you have HSV-1, you can infect other people with your saliva even if you don't have a visible cold sore.
Anyone can get a cold sore. This article will go over the causes of cold sores, the signs and symptoms, and the stages of a cold sore outbreak. It also covers how to treat a cold sore and prevent outbreaks.
Cold Sore Outbreak Stages
Some people will get a cold sore outbreak within a few days of exposure to HSV-1. Other people carry the virus but never have symptoms.
A cold sore can last two to four weeks from the time a person has early symptoms to when the sore is completely healed.
During that time, a cold sore goes through three distinct stages. These stages can vary between first outbreaks and recurrences.
The first stage of a cold sore outbreak lasts one to two days. During this time, symptoms like tingling, itching, or even soreness around the mouth are common.
If you're having a recurrent outbreak, you’ll likely feel a cold sore starting in the same places you've had them before.
Some people only experience the first stage of symptoms and do not develop cold sores.
After a few days, small, hard, fluid-filled blisters begin to form on the lips, nose, cheeks, or other parts of the face.
During the second stage of a cold sore outbreak, the blisters and fluid in them are very contagious, so it's important that you avoid close contact with other people.
The blisters can also spread to other parts of the body. Be especially careful to not touch your eyes after touching a cold sore. If you do touch a cold sore, wash your hands immediately to prevent spreading the virus to other parts of your body.
See a healthcare provider if you have:
- Blisters near the eyes
- Sensitivity to light
- Pain or grittiness in the eyes
Can Children Get Cold Sores?
Children can get cold sores in the mouth which are commonly mistaken for canker sores. If your child has mouth sores, make an appointment with your pediatrician.
In the final stage of a cold sore outbreak, the blisters can come together and burst. The merged, burst blisters turn into small, open sores that ooze fluid.
During the third stage of a cold sore outbreak, the sores are painful and still highly contagious.
After a few days, the open sores will start to dry out and a scab will form. Cold sore scabs can be very itchy and may crack. Try not to bite or pick at cold sore scabs, as it will make the discomfort worse and could lead to infection.
About five to 15 days after the cold sores first appeared, the scabs will begin to fall off and heal.
When To See a Healthcare Provider
The first HSV-1 infection that you get is usually the worst because your body has not yet built up defenses against the virus. If you have these symptoms along with a cold sore, it's important to get medical care:
- High and persistent fever
- Problems swallowing
- Red, irritated eyes
- Sores near the eyes
- Trouble breathing
You should also see a healthcare provider if:
- The cold sores do not go away after 15 days
- The cold sores keep coming back
- You have a weakened immune system and are getting cold sores
After the first infection, the herpes virus stays inside the nerve cells of your face. Unless the virus is triggered and reactivates, you may not have symptoms again.
If you have another outbreak, you will most likely get a cold sore in the same place as you did before. The virus typically reactivates in the same spot each time. However, the symptoms of a cold sore are usually less severe in recurrent outbreaks compared to the first one.
Other Herpes Outbreak Symptoms
During your first cold outbreak, you may also have flu-like symptoms including:
What Causes Cold Sores?
Cold sores are caused by the HSV-1 virus, which is very contagious. You can be exposed to the virus through physical contact with an infected person, such as:
- Intimate contact
- Sharing food or drinks
- Sharing items like lip balm, razors, or towels
How Common Is HSV-1?
Research suggests that 67% of people ages 0 to 49 around the world carry HSV-1.
Research suggests that genetics may make some people more susceptible to cold sores, but researchers are not exactly sure how it works.
Once infected with herpes simplex, you'll have the virus for the rest of your life. Usually, it is not active in your body (dormant). You won't have symptoms until it gets activated.
Factors that contribute to activating the herpes virus include:
- Hormonal changes (e.g., menstruation)
- Dental work
- Exposure to extreme weather
How Cold Sores Are Spread
Cold sores are infectious until they scab over. If you have a cold sore, avoid:
- Touching the sores
- Kissing other people
- Intimate contact with other people such as oral sex
- Sharing food, drinks, or personal items with others
- Having physical contact with anyone who has a weakened immune system
- Having physical contact with children
Preventing Serious Illness in At-Risk People
Cold sores can cause serious health complications in newborns, children, and people who have weakened immune systems. You should avoid contact with at-risk people while you are having a cold sore outbreak.
Cold Sore Treatment
Cold sores are painful, annoying, and for some people, embarrassing. There are some things you can do to take care of a cold sore at home and help it heal faster.
Cold Sore Medications
Certain prescription oral antiviral medications can shorten the duration of a cold sore but they need to be taken within 72 hours of an outbreak to work.
Antiviral medications for cold sores include:
- Famvir (famciclovir)
- Valtrex (valacyclovir)
Your provider might recommend antiviral creams that you put directly to the cold sore, such as:
- Abreva (docosanol 10% cream), available without a prescription
- Denavir (penciclovir 1% cream)
- Zovirax (acyclovir 5% cream)
If your provider wants you to use antiviral creams, make sure that you wash your hands well after you have applied them.
Over-the-counter (OTC) pain relievers such as Advil (ibuprofen) or Tylenol (acetaminophen) can help relieve the pain, swelling, and irritation caused by blisters or open sores during an outbreak.
Your provider can help you get your cold sores under control and avoid potential complications like ocular herpes, which happens when HSV-1 gets into the eyes. Skin infections can also happen with cold sores.
Home Remedies for Cold Sores
There are also some ways to take care of cold sores at home that do not involve taking medication, such as:
- Using a cold compress can reduce pain and irritation during a cold sore outbreak. Apply a cool, damp towel to the sore, not an ice pack. Do the compresses a few times each day for five to 10 minutes at a time.
- Keep the affected area clean and dry. While you might not like how the sore looks, do not put makeup on them.
- Eating and drinking certain foods and beverages may make your cold sore symptoms worse. Avoid acidic foods like citrus, tomatoes, or coffee during an outbreak.
How to Prevent Cold Sores
If you have frequent cold sore outbreaks, your provider may prescribe daily Zovirax or Valtrex to help prevent them.
Depending on what your cold sore triggers are, you might be able to prevent outbreaks without medication. For example, using sunscreen to make sure you don't get too much sun exposure.
It's also important to practice safe sex. Remember, a person with HSV-1 can still spread the virus even if they don't have cold sores.
Cold sores are caused by the HSV-1 virus. Once you contract this virus it stays dormant in your body until something triggers it to reactivate and cause symptoms.
During a cold sore outbreak, you may get blisters around your lips, nose, and cheeks, which eventually break and form an open sore.
During your first cold sore outbreak, you may also have flu-like symptoms. Subsequent outbreaks tend to be milder. See a provider if you have sores near the eyes, frequent cold sores, or if symptoms last more than 15 days.
HSV-1 is very contagious so you need to avoid close contact with others and sharing personal items with them while you are having an outbreak.
Some treatments can shorten the duration of cold sore outbreaks, like prescription oral antivirals and topical antiviral creams. Cold compresses and OTC pain relievers may also help with symptoms, and you need to keep the sores clean to prevent infection.
You might be able to make frequent cold sore outbreaks less likely to happen by taking a daily prescription medication and avoiding your cold sore triggers.
A Word From Verywell
Cold sores can be painful, annoying, and even embarrassing. A cold sore outbreak will usually get better in a few weeks. However, if you get cold sores often, it's important to talk to your provider. They can help you find the right treatment and make sure you take steps to prevent spreading the herpes virus to others.
Frequently Asked Questions
Can cold sores spread through pillows?
Cold sores can spread when a surface gets the HSV-1 virus on it, and you touch that contaminated surface. If you have a cold sore outbreak (or someone in your home does), washing your bedding and clothes can help keep the virus from spreading.
It can also help to throw away your toothbrush after a cold sore outbreak, as the virus could have been transferred to the bristles from your mouth.
What kills cold sore virus on surfaces?
Should you keep a cold sore moist or dry?
It's important to keep a cold sore clean and dry while it's healing. Once the scab forms over the sore, do not scratch at it or pick it off.