Cold Sore Outbreak Overview

Prevalence, Symptoms and Stages, Safety, and Treatment

Table of Contents
View All
Table of Contents

Cold sores are caused by the herpes simplex virus type 1 (HSV). Once you contract the virus, it stays in your system for life. HSV causes tiny blisters to form around the mouth and nostrils. The blisters pop and merge into a cold sore.

Anyone can get a cold sore. Most people contract HSV through physical contact with an infected person. Even without a visible cold sore, a person can infect others via their saliva.

This article discusses the causes, symptoms, and stages of a cold sore outbreak. It also explores how to treat a cold sore and prevent future outbreaks.

Cold Sore Outbreak Symptoms

The herpes simplex virus generally remains dormant in the body. This means you won’t show any symptoms unless it is activated.

Some people experience a cold sore outbreak within a few days of exposure. Other people carry the virus but never experience symptoms.

Symptoms of a cold sore outbreak can include:

  • Red, fluid-filled blisters around the lips, nose, or cheeks
  • Pain in affected areas
  • Fluid secretion from blisters
  • Formation of scabs after blisters have dried
  • Itching and irritation of affected areas

During a first outbreak, you may also experience flu-like symptoms in addition to a cold sore. These include:

  • Mild fever
  • Headache
  • Swollen lymph nodes
  • Muscle aches or general body pain
  • Sore throat
  • Difficulty swallowing
  • Fatigue

The initial HSV infection is usually the most severe. This is because the body has yet to build up its defenses to the virus. If you or a loved one experience the following, see a healthcare provider:

  • High and persistent fever
  • Problems swallowing
  • Red, irritated eyes
  • Sores near the eyes
  • Trouble breathing

After the first infection, the virus remains inside the nerve cells of the face. You may not experience symptoms again, unless the virus is triggered.

If you experience an outbreak in the future, expect to develop a cold sore in the same place. The virus typically reactivates in the same spot each time. Symptoms, however, should be less severe in subsequent outbreaks.

Children can develop cold sores inside the mouth. These are commonly mistaken for canker sores (small lesions in the mouth). If your child begins to develop sores in the mouth, see the pediatrician for an accurate diagnosis.

cold sore stages
Verywell / Brianna Gilmartin 

Cold Sore Stages

A cold sore can last two to four weeks from initial symptoms to complete healing. During that time, it goes through three distinct stages. These stages can vary between first outbreaks and recurrences.

Stage 1

The first stage of a cold sore outbreak lasts one to two days. During this time, tingling, itching, or even soreness around the mouth is common.

If this is a recurrence, you’ll likely feel this in the same locations as previous outbreaks.

In addition, some people only experience this first stage and do not develop cold sores.

Stage 2

After a few days, small, hard, fluid-filled blisters begin to form on the lips, nose, cheeks, or other parts of the face.

At this stage, the blisters and fluid are extremely contagious. Avoid close physical contact with others.

Blisters can also be spread to other parts of the body. If you touch a cold sore, wash your hands immediately to avoid spreading the virus.

Be especially careful to not touch a cold sore then your eyes. Blisters near the eyes, sensitivity to light, and pain or grittiness in the eyes should be evaluated by a healthcare provider.

Stage 3

In the final stage, the blisters may merge together and burst. This results in small, open sores that ooze fluid.

These sores are very painful and highly contagious. After a few days, the open sores begin to dry out and scab.

Cold sore scabs can be very itchy and may crack. Avoid biting or picking at them, as this can worsen discomfort.

The scabs will begin to fall off and heal between five and 15 days after the sores first appear.


Cold sores are infectious until they scab over. If you have a cold sore, avoid:

  • Touching cold sores
  • Kissing
  • Intimate contact (e.g., oral sex)
  • Sharing food, drinks, or personal items
  • Having physical contact with anyone who has a weakened immune system
  • Having physical contact with children

Cold sores can cause serious health issues in newborns, children, and people with a weakened immune system. It is important to take steps to avoid infecting others with HSV.


Cold sores are caused by the herpes simplex virus 1. They are extremely contagious. You can be exposed to the virus through physical contact with an infected person. This includes:

  • Intimate contact
  • Kissing
  • Sharing food or drinks
  • Sharing person items, such as lip balm, razors, or towels

A 2014 report in the journal Human Genome Variation suggests genetics are at play. Researchers uncovered a gene that makes someone more susceptible to cold sores. However, the exact mechanism of such a gene is unknown.

Once infected with herpes simplex, you will have the virus for the rest of your life. Recurrent cold sore outbreaks can be triggered by many different factors. These include:

  • Stress
  • Fatigue
  • Hormonal changes (including menstruation)
  • Illness
  • Dental work
  • Exposure to extreme weather


Research suggests more than half of all Americans ages 14 to 49 carry HSV. Up to 90% of Americans will have at least one cold sore during their lifetime.


Cold sores cause pain, irritation, and even embarrassment. Fortunately, you can treat the pain and symptoms to feel better faster.


Certain prescription oral antiviral medications can shorten the duration of a cold sore. These medicines need to be taken within 72 hours of an outbreak to be effective. These include:

  • Famvir (famciclovir)
  • Valtrex (valacyclovir)

Your healthcare provider may recommend antiviral ointments. These are applied directly to the cold sore and include:

  • Abreva (docosanol 10% cream), available without a prescription
  • Denavir (penciclovir 1% cream)
  • Zovirax (acyclovir 5% cream)

Remember to wash your hands after applying topical medicines.

Over-the-counter pain relievers such as Advil (ibuprofen) or Tylenol (acetaminophen) can alleviate pain, swelling, and irritation caused by blisters or open sores.

Home Remedies and Lifestyle

A cold compress can reduce pain and irritation. Be sure to use a cool, damp towel, rather than an ice pack. Apply compresses a few times each day for five to 10 minutes at a time.

Otherwise, keep the affected area clean and dry. Avoid applying make-up over cold sores.

Stay away from foods that worsen symptoms. Anything acidic, such as citrus, tomatoes, or coffee, can irritate cold sores and prolong symptoms.

When To See a Healthcare Provider

See a healthcare provider if cold sores:

  • Develop near the eyes
  • Reoccur frequently
  • Last for more than 15 days

If you have a cold sore and a weakened immune system, call your healthcare provider.

Your healthcare provider can get cold sores under control so as to avoid potential complications, which may include ocular herpes (HSV-1 transfer to the eyes) and various skin infections.

A Word From Verywell

Fortunately, cold sores tend to be harmless and clear up within a few weeks. If you start to develop symptoms of a cold sore outbreak, and especially if outbreaks are recurrent, talk to your healthcare provider about the best treatment plan for your age, medical history, and lifestyle.  

Was this page helpful?
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ramchandani M, Kong M, Tronstein E, et al. Herpes Simplex Virus Type 1 Shedding in Tears and Nasal and Oral Mucosa of Healthy Adults. Sex Transm Dis. 2016;43(12):756-760.  doi:10.1097/OLQ.0000000000000522

  2. Institute for Quality and Efficiency in Health Care (IQWiG). Cold sores: Overview. 2018.

  3. Montgomery-cranny JA, Wallace A, Rogers HJ, Hughes SC, Hegarty AM, Zaitoun H. Management of recurrent aphthous stomatitis in children. Dent Update. 2015;42(6):564-6, 569-72. doi:10.12968/denu.2015.42.6.564

  4. Krissel JD, Bhatia A, and Thomas A. Cold sore susceptibility gene-1 genotypes affect the expression of herpes labialis in unrelated human subjects. Hum Genome Var. 2014; 1: 14024. doi:10.1038/hgv.2014.24

  5. Fatahzadeh M and Schwartz RA. Human herpes simplex virus infections: Epidemiology, pathogenesis, symptomatology, diagnosis, and management. J Am Acad Dermatol. 2007;57(5):737-63. doi:10.1016/j.jaad.2007.06.027

  6. Formica M, Kabbara K, Clark R, Mcalindon T. Can clinical trials requiring frequent participant contact be conducted over the Internet? Results from an online randomized controlled trial evaluating a topical ointment for herpes labialis. J Med Internet Res. 2004;6(1):e6.

Additional Reading