difference between cold sore and canker sore

Okay so, you’ve got a sore somewhere around your mouth and you’re like… uhh what is this thing? Is it a cold sore? Or is it a canker sore? Aren’t they the same thing? (Nope. Not even close. Kinda.)

Even tho they both suck (and can make eating painful and awkward), cold sores and canker sores are totally different. Let’s break it down in a non-doctor-y way so it actually makes sense.

First Off, Where Is It?

Probably the fastest way to tell the diff:

• If it’s outside your mouth, like on your lips or just near it = cold sore

• If it’s inside, like on your gums, cheek, tongue or inner lip = canker sore

This already clears up like half the confusion for most people.

️ What Even Causes These?

Cold Sore = Herpes (but chill, it’s common)

Cold sores are caused by the herpes simplex virus (HSV-1). Yes, that sounds scary but like, a LOT of people have it. Most get it in childhood, and the virus just hangs around in your body forever after that. You don’t always get symptoms tho.

Things that trigger cold sores:

• Stress (classic)

• Being sick

• Sunburn

• Periods (ugh)

• Not sleeping enough

• Kissing someone who has it (even if there’s no sore showing yet)

Canker Sore = Nobody Really Knows Tbh

Canker sores aren’t viral. So they’re not contagious and don’t come from kissing or sharing drinks or anything like that.

Stuff that can trigger them:

• Stress again (why not )

• Accidentally biting your cheek or tongue

• Spicy or acidic foods

• Brushing too hard

• Hormone changes

• Sometimes even toothpaste ingredients (like SLS — look it up)

Sometimes they just… show up. For no reason. And hurt like hell.

What Do They Look Like?

Cold Sore:

• Usually starts with a tingle or burny feeling

• Then a cluster of small blisters shows up on/around lips

• They pop, crust over, and heal (gross but true)

• Can be painful and also itchy

Canker Sore:

• Round or oval sore inside the mouth

• White or yellow in the center, with a red ring around it

• Hurts when you eat salty, spicy or sour stuff

• Doesn’t blister or leak or anything

Are They Contagious?

• Cold sore: Yep. 100%. Don’t kiss anyone, don’t share forks, spoons, water bottles, lip balm, etc. You can spread the virus even when the sore isn’t visible, so yeah, kinda sneaky.

• Canker sore: Nah. Totally safe. Not viral, not contagious. Just annoying.

How to Treat Them (or at least make them less annoying)

Cold Sores:

• Use antiviral creams (like acyclovir, if you catch it early)

• You can also get prescription meds if you get them a lot

• Lip balm with SPF can help prevent future flare-ups (sun is a trigger)

• Cold compress helps too

• Don’t pick at it. Seriously. Don’t.

They usually go away in like 7–10 days, sometimes quicker if you treat early.

Canker Sores:

• Salt water rinse (yes it stings. But helps.)

• Over-the-counter gels or numbing stuff

• Avoid hot, spicy or acidic foods for a few days

• Ice cubes, popsicles – numbs the pain a bit

• Eat soft stuff. Mashed potatoes are the MVP here.

They heal in 5–7 days most times, sometimes up to 10.

TL;DR (Too Long; Didn’t Read)

When to Call a Doctor?

• Cold sore that’s spreading fast or not healing

• Canker sores that keep coming back like every other week

• Really big sores or ones that make it hard to eat/drink

• Fever along with mouth sores

• Baby or toddler has a cold sore (should get checked)

Final Thoughts (from someone who’s had both )

Both of these are super annoying, painful, and just make life more difficult than it needs to be. Cold sores look worse, but canker sores feel worse (especially when they’re in a terrible spot, like under your tongue ).

The best thing you can do is try to avoid your triggers (if you know them), treat them early, and not freak out. They usually heal on their own. And don’t let Google convince you you’re dying.