When Does A Cold Sore Stop Being Contagious? - Medical News Today
Maybe your like
- Health Conditions
Health Conditions
- Alzheimer's & Dementia
- Anxiety
- Asthma & Allergies
- Atopic Dermatitis
- Breast Cancer
- Cancer
- Cardiovascular Health
- COVID-19
- Diabetes
- Endometriosis
- Environment & Sustainability
- Exercise & Fitness
- Eye Health
- Headache & Migraine
- Health Equity
- HIV & AIDS
- Human Biology
- Leukemia
- LGBTQIA+
- Men's Health
- Mental Health
- Multiple Sclerosis (MS)
- Nutrition
- Parkinson's Disease
- Psoriasis
- Sexual Health
- Ulcerative Colitis
- Women's Health
- Health Products
Health Products
All- Nutrition & Fitness
- Vitamins & Supplements
- CBD
- Sleep
- Mental Health
- At-Home Testing
- Men’s Health
- Women’s Health
- Discover
News
- Latest News
- Medicare 2026 Costs
Original Series
- Medical Myths
- Honest Nutrition
- Through My Eyes
- New Normal Health
Podcasts
All- Artificial sweeteners and brain aging: What we know so far
- Does the Mediterranean diet hold the key to longevity?
- AMA: Registered dietitian answers 5 key questions about fiber and weight loss
- Health misinformation and disinformation: How to avoid it
- Brain health, sleep, diet: 3 health resolutions for 2025
- 5 things everyone should know about menopause
- Tools
General Health
- Drugs A-Z
- Health Hubs
- Newsletter
- Medicare Plans by State
Health Tools
- Find a Doctor
- BMI Calculators and Charts
- Blood Pressure Chart: Ranges and Guide
- Breast Cancer: Self-Examination Guide
- Sleep Calculator
Quizzes
- RA Myths vs Facts
- Type 2 Diabetes: Managing Blood Sugar
- Ankylosing Spondylitis Pain: Fact or Fiction
- Connect
About Medical News Today
- Who We Are
- Our Editorial Process
- Content Integrity
- Conscious Language
Find Community
- Bezzy Breast Cancer
- Bezzy MS
- Bezzy Migraine
- Bezzy Psoriasis
Follow Us
Medically reviewed by Avi Varma, MD, MPH, AAHIVS, FAAFP — Written by Jayne Leonard — Updated on February 9, 2023- Transmission
- Triggers
- Treatment
- Prevention
- Outlook
- Summary
Cold sores result from a virus and are usually contagious for around 15 days. Generally, a person can pass on the underlying virus while a cold sore is present.
Cold sores are fluid filled blisters that appear on the lips and around the mouth. They develop in response to a common viral infection.
The first sign of a developing cold sore tends to be a burning or tingling sensation in the area. This may be 1–2 days before the onset of visible blisters.
Even before it breaks out, it may already be transmissible.
The cold sore will appear as a cluster of blisters on the surface of the skin. Typically, these blisters will burst, resulting in an open and painful sore. A scab then forms over the wound.
The entire process usually takes around 7–12 days, though the cold sores may last for up to 15 days.
In this article, we explore how people contract and transmit the cold sore virus. We also provide information on cold sore symptoms, prevention tips, and treatment options.
Transmission
Share on PinterestThe herpes simplex virus type 1 (HSV-1) is what causes cold sores.
According to the National Institutes of Health (NIH), more than 50% of people in the United States have contracted HSV-1 by the time they reach their 20s. Most people contract it during childhood.
HSV-1 is highly contagious. People can transmit it to another person by kissing or sharing utensils, towels, or other personal care items. The virus can then enter the body through a small cut in the skin.
Once a person has HSV-1 in their system, it is there for life, as there is currently no cure. The virus can remain dormant for long periods but may reactivate at any point.
In some cases, however, the virus may never become active. Many people with the virus do not develop cold sores.
A person can transmit HSV-1 to others when the virus is inactive. However, a person is much more likely to pass on HSV-1 when cold sores are present.
Cold sore triggers
Many triggers can cause the virus to reactivate. They may include:
- dental work
- emotional distress
- fever
- hormonal changes, such as from menstruation
- infection
- injury
- stress
- exposure to sunlight
- surgery
People who develop cold sores may experience them less frequently as they age. According to the American Academy of Dermatology, HSV-1 tends to reactivate less often in people over 35.
Reactivation also tends to be more common in the first year after the initial outbreak.
Signs of a new outbreak
Most people contract HSV-1 during childhood. However, some contract the virus later in life.
When someone initially gets the virus, they may experience the following symptoms:
- a burning sensation before the appearance of painful mouth sores
- aches and pains
- fever
- flu-like symptoms
- headache
- nausea
- sore throat
- swollen lymph nodes
Symptoms typically last for up to 2 weeks, though some people may not develop any symptoms at all.
Reactivation symptoms and stages
Many people experience a burning, itching, or tingling sensation on or around the lips 1–2 days before a cold sore appears. This is called the prodrome stage.
During the next stage, fluid filled blisters will develop. Around a third of people experience cold sores at the same location each time.
Within 48 hours, the blisters tend to burst and leak fluid. This stage can be painful and may last for around 3 days. This is when the cold sores may be most contagious.
In the final stage, a scab forms over the wound. The scab may crack or bleed until it finally clears up. Once the skin is clear of the cold sore, it is no longer possible to transmit it to someone else.
Treatment
Most cold sore outbreaks do not require a visit to the doctor. They typically clear up on their own within 7–12 days.
Trying home treatments during this time can reduce discomfort. They can also prevent transmission to other parts of the body and other people.
Home remedies
Some home remedies include:
- Trying topical antiviral medications: Some antiviral cold sore medications, such as docosanol (Abreva), are available over the counter.
- Applying sunscreen: Protecting cold sores from the sun helps prevent further skin damage. Ideally, people should apply a lip balm with a sun protection factor (SPF) of 30 or higher.
- Taking pain relief medications: Taking over-the-counter pain relievers, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol), may reduce discomfort.
- Applying ice: Applying an ice pack to the area may help bring down pain and swelling. People should wrap ice packs in a clean towel first. Applying ice directly to the skin can cause more damage.
- Trying petroleum jelly: Applying this to cold sores may aid the healing process.
- Making dietary changes: Eating acidic, salty, and spicy foods can cause burning pain if they touch the sores. Therefore, it can be helpful to avoid these foods until the sores heal.
Medical treatments
People should see their doctor if cold sores are severe or persist beyond 15 days. A doctor may recommend:
- prescription antiviral medication in the form of topical cream or oral medication
- intravenous antiviral medications (for severe outbreaks)
- pain relief medications
People who experience regular outbreaks may need to take prescription medication to keep their symptoms under control.
A person should also see a doctor for cold sore treatment if they:
- develop numerous sores
- develop sores near the eyes or on the hands or genitals
- experience severe pain with the sores
- are pregnant
- have atopic dermatitis
- have cancer and are undergoing chemotherapy treatment
- have HIV, AIDS, or another condition that weakens the immune system
- take an immunosuppressant medication
In these cases, the cold sores may not go away on their own. Medical treatment can also help prevent complications.
Prevention tips
The following tips can help limit the spread of HSV-1:
- Avoid kissing other people while the sores are active.
- Avoid engaging in oral sex and any other intimate contact while the sores are active.
- Do not share personal care products, such as razors, lip balms, and towels, with other people.
- Do not share utensils, drinks, or foods.
- Refrain from touching the sores unless necessary, such as when applying cream.
Wash the hands immediately after touching a cold sore and regularly throughout the day.
When cold sores are present, people should take extra precautions during contact with people who have weaker immune systems. This includes children and newborn babies, whose immune systems have had less time to develop.
People can also take measures to reduce their chance of experiencing a cold sore outbreak. These include:
- wearing sunscreen or lip balm with an SPF of 30+ every day
- practicing yoga or meditation to help reduce stress
- getting enough sleep each night
- taking any prescribed antiviral medications at the first sign of an outbreak
Outlook
There is currently no cure for cold sores. This means that once a person contracts HSV-1, they will have it for life.
However, not everyone who has the virus will develop cold sores.
People who are prone to cold sores can try to reduce their exposure to potential triggers. These include stress, sunlight, and infections.
Taking prescription medication may be helpful for those who experience regular outbreaks.
Summary
HSV-1, the virus that causes cold sores, is very common among adults in the U.S. Most people who have it contract the virus in childhood.
Cold sores are highly contagious from the time the first symptom appears. This is usually 1–2 days before the sore becomes visible. The virus can remain contagious for up to 15 days.
During an outbreak, people should be careful not to transmit the virus to others.
Trying home remedies can help relieve the symptoms. If these are not effective, medical treatments can reduce pain and speed up healing.
Those who have concerns about cold sores or other mouth lesions should see their doctor.
- Dermatology
- Infectious Diseases / Bacteria / Viruses
How we reviewed this article:
SourcesMedical News Today has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.- Cold sores. (2020).https://www.nhs.uk/conditions/cold-sores/
- Cold sores: Diagnosis & treatment. (n.d.).https://www.aad.org/public/diseases/a-z/cold-sores-treatment
- Ebert Brand, J. (2011). Common sense about cold sores.https://www.myamericannurse.com/common-sense-about-cold-sores/
- National Institutes of Health. (2008). Learning how cold sore viruses hide [Press release].https://www.nih.gov/news-events/nih-research-matters/learning-how-cold-sore-viruses-hide
- Oral herpes. (n.d.).https://www.hopkinsmedicine.org/health/conditions-and-diseases/herpes-hsv1-and-hsv2/oral-herpes
Share this article
Medically reviewed by Avi Varma, MD, MPH, AAHIVS, FAAFP — Written by Jayne Leonard — Updated on February 9, 2023Latest news
- Experimental drug reverses Alzheimer's in mice
- ADHD Drugs Like Adderall May Work Differently Than Previously Thought
- Body clock disturbances may contribute to dementia risk, evidence suggests
- 10 minutes of intense exercise may help treat colorectal cancer
- Hot flash treatment can slow breast cancer growth, trial finds
Related Coverage
- What causes recurrent cold sores?Medically reviewed by Alana Biggers, M.D., MPH
Many people have cold sores throughout their lives, but some factors can make it easier for them to recur. Learn about why cold sores recur here.
READ MORE - Lysine for cold sores: Does it work?Medically reviewed by Dena Westphalen, PharmD
Lysine is an amino acid that may help prevent cold sores. Most people get lysine from their diet. In this article, Learn more about whether it is…
READ MORE - How to get rid of a cold soreMedically reviewed by Kristen M. Moyer, MD
Cold sores have no cure, but a range of medications can ease the discomfort and reduce the duration of an outbreak. Home remedies may help. Learn more…
READ MORE - What causes cold sores, and can they reappear?Medically reviewed by Lauren Castiello, MS, AGNP-C
Herpes simplex virus type 1 (HSV-1) causes cold sores. Cold sores may recur throughout a person's lifetime. Learn more about the triggers that can…
READ MORE - Epstein-Barr virus: Symptoms and treatment
Epstein-Barr virus is very common. Most people who contract the virus do not develop symptoms, but others get mononucleosis or other conditions.
READ MORE
Tag » When Are Cold Sores Not Contagious
-
Are Cold Sores Contagious? - Abreva
-
When Does A Cold Sore Stop Being Contagious? - Healthline
-
Cold Sores - NHS
-
When Is A Cold Sore No Longer Contagious? | Colgate®
-
When Is A Cold Sore No Longer Contagious? | Colgate®
-
How Long Are Cold Sores Contagious? | Compeed®
-
When Does A Cold Sore Stop Being Contagious? - Quantum Health
-
How Long Are Cold Sores Contagious? - PlushCare
-
How Long Is A Cold Sore (Herpes On Lip) Contagious?
-
Cold Sore - Symptoms And Causes - Mayo Clinic
-
How Long Are Cold Sores Contagious | CareNow®
-
Are Cold Sores Contagious? Here's What To Know
-
How Long Are Cold Sores Contagious? Don't Cancel Your Plans ...