Cold sores are red, fluid-filled blisters that usually appear near or around your mouth, usually at the worst possible time (think the morning before you’re about to give a big presentation at work or the moment before a date).

They develop in specific stages that can help you spot them. These sores can be caused by the herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2) and can transmit to others easily, even when the sore isn’t yet visible. So it’s important to be aware when they’re developing.

Though they typically occur around the lips, they can actually appear anywhere on the skin, with the next most common location being around and up the nose. Ouch.

Cold sores usually resolve without leaving a scar within 5 to 15 days.

If you regularly experience cold sores, then you can probably tell when one is getting ready to make its grand appearance.

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You may be an old hand with cold sores and spot a flare from miles away. However, if you’re new to them, you might not know it’s a cold sore at first. But it can still spread during the early stages.

Stage 1: Tingling

You might feel an unexplained tingling around your mouth, but otherwise, the area probably doesn’t look any different. Some people don’t experience this stage though.

The cold sore is about to appear. This is a good time to attempt treatment — it can reduce the severity of the cold sore and shorten the duration of its stay (lol, bye). It can even prevent the cold sore from coming out altogether.

Stage 2: Blistering

Anywhere from a few hours to 2 days after the tingling, one or two fluid-filled blisters will appear on the skin’s surface. The skin under and around the blisters will be red.

Stage 3: Weeping

After a few days, the cold sore will break open and will look red and shallow.

🎼 While my cold sore gently weeps…🎤

Stage 4: Crusting

At this stage, the blister starts to dry out. It will look yellow or brown.

Stage 5: Healing

Aah, finally. 🙏

During the healing stage, the crusted blister will scab over. It will slowly start to disappear as it flakes away.

Our handy visual guide will help you understand the appearance of each stage.

Here’s what to expect during a cold sore breakout — from beginning to end.

Tingling

A cold sore begins before you can even see it. If you feel an unexplained tingling around your mouth, a cold sore might be coming out to play.

This is usually one of the first signs that a cold store is developing. You might also feel a burning or itching.

At this point, you can and should start treating your cold sore. While treating it right away will not prevent the sore from forming, it could reduce its severity and how long it lasts.

Managing stage one

At this phase, oral medication is the most effective remedy.

If you experience cold sores a lot, talk to your doctor about taking daily medication to prevent or limit outbreaks. They would prescribe one of the following options:

  • Acyclovir (Zovirax)
  • Valacyclovir (Valtrex)
  • Famciclovir (Famvir)

If you only get cold sores once in a while, the preferred treatment is still oral medication. But you don’t need to take it daily between cold sores.

Unless your doctor has suggested otherwise, applying a topical cream might provide extra benefits alongside oral meds. These include:

  • Doscosanol (Abreva), which is available over the counter
  • Acyclovir (Zovirax), by prescription only
  • Penciclovir (Denavir), by prescription only

The first stage of a cold sore might be painful or uncomfortable. If so, you can try taking an over-the-counter (OTC) pain reliever like acetaminophen (Tylenol) or ibuprofen (Advil). You might also get relief from a cream like lidocaine or benzocaine.

Blistering

After about a day or 2 of the tingles, your cold sore will become visible in the blistering stage.

At this point, one or more blisters full of clear fluid will appear on the skin’s surface. The skin around the blisters will be red. They can develop on or inside your mouth (and even in your throat — no thanks).

Managing stage two

It may be a good idea to start using a pain reliever, oral medication, or topical cream at this stage (if you weren’t already during stage one). You should also drink as much water as possible.

Staying hydrated is important, especially when your mouth is sore.

Throughout every stage of cold sore symptoms, you might feel discomfort while eating. It’s best to avoid foods that will irritate the sore, such as:

  • citrus
  • spicy foods
  • salty foods
  • hot liquids

Weeping

The third stage comes a few days after the cold sore appears on your skin. It will break open and will look red and shallow.

During this stage, HSV-1 is likely to pass from one person to the next. This is because the cold sore releases its fluid (yuck).

Managing stage three

If you haven’t started using a topical or oral pain reliever to help with symptoms, this is a good time to kick off your relief. You can also soothe pain and discomfort with a cold or warm compress.

Crusting

Once the weeping stage is over, your blister will begin to dry out. So begins the crusting stage.

As the blister dries, it will look yellow or brown.

Managing stage four

For relief, you can use:

  • a cold compress
  • a warm compress
  • zinc oxide ointment

Healing

The healing stage is the final stage. (And now, the act you’ve all been waiting for…)

The crusted blister will begin to scab over as it heals. Since this can be uncomfortable, you can try to keep the scab soft by using emollients containing zinc oxide or aloe vera.

As the scab flakes away, it will slowly clear up. People usually reach this stage around 5 to 15 days after noting symptoms.

Cold sores generally don’t leave a scar behind. (Hooray!)

Cold sores develop because of the herpes simplex virus — either type 1 (HSV-1) or type 2 (HSV-2).

The sores that develop after either virus enters the body are very similar in appearance. Both can cause sores on the genitals or mouth.

The herpes virus is highly contagious and can spread even if the sores aren’t visible. You can spread herpes through close contact like kissing, oral sex, or sharing cosmetics or food.

Herpes is also extremely common: up to 90 percent of adults have the virus, and as many as 50 percent of people develop the condition by the time they’re in kindergarten. Not everyone with herpes will experience cold sores.

There is no cure for herpes. It might be dormant in your body for years before a cold sore ever appears on the skin. Once sores heal, the virus can go back to being dormant until a trigger reactivates it.

Triggers

After exposure to the herpes virus, you will generally get a cold sore after triggers cause the virus to flare up. These triggers can be different for everyone.

Some examples include:

Areas that cold sores develop

Cold sores due to HSV-1 generally form on or in your mouth. They can also develop on your cheeks, nose, and eyes.

It’s possible to treat the occasional cold sore at home. Over-the-counter medication can speed up the healing process and provide relief.

If you get cold sores on a fairly regular basis, you may want to see your doctor for prescription medication. This can reduce how often they occur and make them less severe when they do.

You should seek consultation if a cold sore:

  • spreads to your eye (this is an emergency and can cause vision loss)
  • develops alongside a fever
  • doesn’t clear up in a week or 2
  • causes crusted or oozing skin

Cold sores are red, fluid-filled blisters caused by the herpes simplex virus.

There are five stages to a cold sore: tingling, blistering, weeping, crusting, and healing.

Cold sores are a result of the herpes virus, which can lay dormant in your body until a sore comes up on the skin. Different factors can trigger a cold sore, such as a weakened immune system, stress, and hormonal changes.

Cold sores can develop on or inside the mouth, and less commonly on the cheeks, nose, and eyes.

You should see a doctor if you regularly get cold sores. A doctor can also help if they travel to your eye, don’t go away after a week or 2, or become surrounded by crusty skin.