Updated on February 22, 2024
6 min read

5 Stages of Cold Sores and What to Do

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5 Stages of a Cold Sore (How They Form)

Not everyone with cold sores experiences the same set of symptoms or symptoms in the same order.

But there are 5 distinct cold sore stages. A cold sore is contagious from the time you first experience symptoms until it’s completely healed.

Typical cold sore stages include: 

Stage 1: Tingling 

During this cold sore stage, many people feel an odd sensation where a cold sore develops 12 to 24 hours before they’re noticeable. 

Some people describe this sensation as:

  • Burning
  • Tingling with numbness
  • Itching
  • Stinging
  • Throbbing

The skin often becomes red, inflamed, and painful as blisters form. It can also become dry and itchy.

People who experience these early symptoms or warning signs of cold sores may never actually have a cold sore outbreak. Applying OTC antiviral ointments for cold sores or taking prescription antiviral medications at this stage may prevent them from forming and improve the healing process.

During first outbreaks, it can take up to 20 days for symptoms to develop after being exposed to the cold sore virus. 

Stage 2: Blistering

Tiny, painful, fluid-filled blisters begin to form. Blisters may appear alone or as multiple blisters close together in groups or patches. 

At first, a cold sore blister appears clear, then becomes pus-filled and cloudy during this stage. The skin blisters and underneath is typically redder than usual. Do not try to pop, irritate, or break open blisters.

Cold sores typically develop on the lips or around the mouth. But a cold sore can form on the nose, cheeks, and other body parts. Talk to a doctor if cold sores develop on the genitals. 

Sores may also develop in the mouth during your first outbreak.

In rare cases, cold sores impact the eyes. Without proper, early treatment, herpes eye infections can affect your eyesight. 

Seek immediate medical attention if a cold sore develops near or on the eye, or the eyes become:

  • Painful
  • Sensitive to light
  • Gritty
  • Runny

Stage 3: Weeping

Cold sore blisters burst and leak, or weep, clear to yellowish-colored fluid for a few days. Sometimes blisters merge before they rupture.

Blisters tend to rupture 2 to 3 days after they develop or 48 hours after warning symptoms develop. 

Once they rupture, blisters leave behind shallow, red, exposed, and ulcerated sores. The skin around the sores is often painful, dry, and irritated during this period.

Cold sores are most contagious during the weeping stage. Avoid picking or touching weeping sores to prevent them from worsening, spreading, or becoming infected with bacteria.

Stage 4: Crusting

Like other wounds, after cold sore blisters rupture, they crust and form scabs. Crusting and scabbing typically occur 4 to 5 days after cold sores appear. Scabs may crack or bleed a bit as they heal.

Do not try to pick or pull off scabs or crusting. Applying hydrating creams or ointments can help scabs from becoming too itchy.

Stage 5: Healing

During the final stage of a cold sore, scabs fall or flake off on their own after a few days. The skin underneath scabs tends to be redder, pinker, or more sensitive than normal. It often takes 1 to 3 weeks for sores to heal completely. 

Most cold sores don’t leave permanent scars unless they’re severe or extensive. But scabs are often painful and irritating during this stage. 

What Causes Cold Sores?

Cold sores are tiny, fluid-filled blisters that usually form on the lips. They are also called fever blisters or oral herpes.

Cold sores are contagious and spread through close contact with bodily fluids or secretions. They are most contagious when the blisters are oozing, but can spread even when invisible.

The herpes simplex virus 1 (HSV-1) causes most cold sores. But the herpes simplex virus 2 (HSV-2) can also cause it. More than 50% of people in the U.S. have the cold sore virus.

After a cold sore heals, the herpes simplex virus becomes dormant (inactive) and lives in nerve cells. Certain factors can trigger the herpes virus to reactivate and cause sores, typically in the same place as before.

Common triggers for cold sores include:

  • Fever
  • Illness
  • Sunlight, wind, and cold weather
  • Stress
  • Immune changes
  • Injury
  • Fatigue
  • Menstruation
  • Dry, damaged, or cracked lips
  • Certain foods
  • Dental work
  • Cosmetic procedures
  • Gastrointestinal problems

Common Symptoms

Only around 20 to 40% of people infected with herpes develop cold sores. People usually develop different symptoms depending on whether it’s their first cold sore outbreak.

During your first outbreak, you may experience the following initial symptoms for 1 to 2 weeks:

  • Fever
  • A burning sensation in the mouth followed by the formation of painful sores on the lips, gums, tongue, or throat
  • Sore throat and pain when swallowing
  • Headache
  • Painful gums
  • Red or swollen gums
  • Muscle aches
  • Swollen lymph nodes
  • Nausea
  • Bad breath

During subsequent herpes outbreaks, most people develop painful, hard blisters that ooze clear or yellow fluid once they burst.

How Long Do Cold Sores Last?

Cold sores normally last several days before rupturing and forming a scab. Most cold sore scabs take 1 to 3 weeks to heal completely. 

If cold sores are recurring, they are often less severe and only take a week to heal.

When to See a Doctor for a Cold Sore 

Most cold sores don’t require medical attention. 

Talk to a doctor if you have:

  • Cold sores that don’t heal after 2 to 3 weeks
  • An immune condition or weakened immune system
  • Severe symptoms or frequent, large, or numerous cold sores
  • Cold sores on the eyes, genitals, or other body parts
  • A fever, spreading redness, or discolored pus


A doctor will typically diagnose a cold sore by looking at it. They may also take a swab of the sore and send it away for testing.

Medical Treatments 

There’s no cure for herpes, but some medications can help reduce symptoms and speed up healing.

People with frequent cold sores or a high risk of complications can take antiviral medication routinely or before exposure to triggers. If oral antibiotics are not effective, you can take antiviral medications intravenously (IV). 

Home Remedies

Some at-home remedies can reduce cold sore symptoms and improve the healing process.

At-home remedies for cold sores include:

  • Applying cold compresses
  • Taking oral OTC pain or anti-inflammatory medications, but not aspirin
  • Applying OTC topical treatments with numbing agents, like lidocaine, by using a clean Q-tip or cotton swab
  • Consuming cold, soft foods and drinks
  • Avoiding acidic, salty, or spicy foods
  • Applying sunscreen or lip balm with SPF 
  • Avoiding or limiting exposure to triggers
  • Managing stress
  • Not touching cold sores 
  • Applying OTC cold sore patches that protect the skin during healing
  • Drinking plenty of fluids to prevent dehydration
  • Applying zinc ointments or creams to scabs
  • Washing your hands frequently 

Some OTC creams and ointments can prevent cold sores if you apply them before they appear (when warning signs develop). They can also improve healing. 

Prevention Tips

There are steps you can take to reduce the risk of being infected with the herpes virus. There are also ways to prevent cold sores and recurrent outbreaks. 

Common tips include:

  • Avoid skin-to-skin or intimate contact with someone with cold sores 
  • Wash your hands before touching yourself or others when you have cold sores
  • Avoid sharing personal items, such as those that touch the skin 
  • Get enough sleep
  • Protect your skin from harsh sun, wind, or cold
  • Maintain a healthy, balanced diet
  • Avoid contact with sick people

Last updated on February 22, 2024
9 Sources Cited
Last updated on February 22, 2024
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. American Academy of Dermatology Association “Cold sores: Overview.” American Academy of Dermatology Association
  2. Ceders Sinai “Cold sores.” Cedars Sinai
  3. Cleveland Clinic “Cold sores.” Cleveland Clinic
  4. Johns Hopkins Medicine “Cold sores.” Johns Hopkins Medicine.
  5. Mayo Clinic “Cold sores.” Mayo Clinic
  6. National Health Service “Cold Sores.” National Health Service.
  7. Nemours Teens Health “Cold sores(HSV-1).” Nemours Teens Health
  8. StatPearls “Herpes Simplex Type 1.” StatPearls
  9. University of Michigan Health Service “Cold and canker sores.” University of Michigan Health Service
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