GET THE FACTS
on cold sores
GET THE FACTS
on cold sores
What are cold sores?
Cold sores are viral infections caused by the herpes simplex virus (HSV-1) and appear as small, painful, fluid-filled blisters (also called vesicles). They are very common and usually self-diagnosable. Most often, cold sores appear on the lips, although they can also appear on noses, cheeks or fingers. While some people never develop any symptoms from HSV-1, others may have periodic outbreaks.
Stages of an outbreak
To view a visual of each stage of an outbreak, click the corresponding red circle.
First signs
A tingling, itching or burning sensation is experienced on or around the lips about 12–24 hours before the cold sore develops.
Blistering
Blisters form, causing the area to become red, swollen and painful.
Weeping
The most contagious and painful stage. Over 2–3 days, blisters rupture and ooze clear or slightly yellow fluid.
Crusting
Around 4–5 days after the cold sore appears, a crust forms and it scabs over. Cracking or bleeding is common.
Recovering & healing
A series of scabs form on the area, which flake as the cold sore heals. Left untreated, healing process typically takes 1–2 weeks.
First signs
A tingling, itching or burning sensation is experienced on or around the lips about 12–24 hours before the cold sore develops.
Blistering
Blisters form, causing the area to become red, swollen and painful.
Weeping
The most contagious and painful stage. Over 2–3 days, blisters rupture and ooze clear or slightly yellow fluid.
Crusting
Around 4–5 days after the cold sore appears, a crust forms and it scabs over. Cracking or bleeding is common.
Recovery & healing
A series of scabs form on the area, which flake as the cold sore heals. Left untreated, healing process typically takes 1–2 weeks.
Causes and triggers
HSV-1, the virus that causes cold sores, is contagious and spreads easily. There is currently no cure.
Triggers may include:
skin injury
viral infection or fever
hormonal imbalance, such as menstruation
stress or fatigue
changes in immune system
exposure to sunlight, wind, cold and hot weather
Symptoms
Before a blister appears, some people may experience a sore throat, fever, swollen glands or painful swallowing.
Cold sore symptoms may include:
• Mouth: sore lip, tingling, tingling lips, burning sensation or ulcers, sensitive gums
• Skin: blister or cluster of blisters and/or a rash, ulcers or redness
FAQs
Cold sores are caused by certain strains of the herpes simplex virus (HSV-1).
HSV-1 can be spread by kissing or touching someone with cold sores or by sharing eating utensils, towels, lip balm or other personal items with an infected person. During an outbreak, wash your hands carefully before touching yourself and other people, especially babies.
Q&A Sources:
1. Johns Hopkins Medicine. Oral herpes. Accessed August 17, 2021. https://www.hopkinsmedicine.org/health/conditions-and-diseases/herpes-hsv1-and-hsv2/oral-herpes
2. Mayo Clinic. Cold sore. Accessed August 17, 2021. https://www.mayoclinic.org/diseases-conditions/cold-sore/symptoms-causes/syc-20371017
3. Cleveland Clinic. Cold Sores. Accessed August 17, 2021. https://my.clevelandclinic.org/health/diseases/21136-cold-sores
**In typical cases. Results may vary.
