What is a cold sore?
- Cause
- Herpes simplex virus, usually HSV-1
- Heals in
- About 1–2 weeks
- Contagious?
- Yes, until fully crusted and healed
- Treatment
- Antivirals work best started early
Cold sores, or fever blisters, are small fluid-filled blisters on or around the lips caused by the herpes simplex virus, usually HSV-1. Most people are exposed to the virus in childhood.
After the first infection, the virus stays dormant in the nerves and can reactivate, often triggered by stress, illness, sun exposure, fatigue or hormonal changes.
Stages of a cold sore
Cold sores tend to follow a predictable pattern:
- Tingling, itching or burning on the lip a day or two before
- Small, painful fluid-filled blisters
- Blisters that break and ooze
- A yellow crust that forms as it heals
- Healing without a scar in 1–2 weeks
Get prompt care if you have
These need more than routine cold sore treatment:
- A sore near or in your eye, or eye pain
- Sores spreading over a large area of skin, especially with eczema
- A weakened immune system and a severe outbreak
Treating cold sores
Cold sores heal on their own, but antiviral medicine can shorten an outbreak and ease symptoms, especially when started at the first tingle.
| Antiviral treatment | Can shorten an outbreak when started early |
|---|---|
| Docosanol cream | Over the counter; applied several times a day at the first sign |
People with frequent outbreaks can discuss keeping medicine on hand or taking a daily antiviral.
Easing discomfort
- Apply a cool compress
- Use a lip balm with sunscreen
- Take acetaminophen or ibuprofen for pain, if safe for you
- Avoid touching or picking at the sore, and wash your hands after applying cream
Is an online cold sore visit right for you?
Online care is often a good fit if you:
- Feel the tingle of a cold sore coming on
- Get cold sores regularly and want medicine on hand
- Have a typical cold sore on the lip
Get in-person care if you:
- Have a sore near your eye
- Have a weakened immune system
- Have sores that don't heal within 2 weeks
How PulseCareMD can help
A PulseCareMD visit is a fast way to get antiviral treatment started while it can still make a difference. Your visit fee covers the consultation.
Describe your symptoms
Tell us when the tingling started and how often you get cold sores.
A provider reviews it
A licensed provider reviews how early you caught the outbreak, since timing shapes treatment. Many visits are reviewed within 2–3 hours.
Start treatment
A treatment plan from your provider if appropriate.
Preventing outbreaks and spread
You can lower how often cold sores appear and avoid passing them on:
Protect your lips from sun
Use lip balm with SPF.
Know your triggers
Stress, illness and lack of sleep are common ones.
Avoid kissing during outbreaks
Especially babies and people with weakened immune systems.
Don't share
Avoid sharing cups, utensils, lip balm or towels during an outbreak.
Frequently asked questions
When to get urgent care
Seek same-day in-person care if you have:
- A sore near your eye, or eye pain or vision changes
- Widespread sores with fever, especially with eczema
- Severe pain or difficulty eating and drinking