You wake up. There's a suspicious bump near your lip. And now you're standing approximately two centimetres from the bathroom mirror trying to answer one question:

Cold sore or pimple?

They can sometimes appear in similar areas, but cold sores and pimples develop for completely different reasons.

Here's what to look for.

What causes a cold sore?

Cold sores are usually caused by HSV-1, or herpes simplex virus type 1.

A recurring cold sore is caused by reactivation of the virus already present in the body.

They commonly develop on or around the lips and typically progress through recognisable stages.

What causes a pimple?

Pimples are associated with blocked pores and inflammation involving oil, dead skin cells and bacteria.

They can occur almost anywhere there are hair follicles and sebaceous glands, including around the mouth and chin.

Clue #1: What did it feel like before it appeared?

Cold sores often announce themselves before you can actually see much.

You might notice:

• Tingling
• Burning
• Itching
• Sensitivity
• Tightness

This early period is known as the prodrome stage.

Pimples can also feel tender before becoming visible, but that characteristic tingling or burning sensation can be a clue that you're dealing with a cold sore.

Clue #2: What does it look like?

Cold sores typically develop into one or more small, fluid-filled blisters, sometimes clustered together.

A pimple may develop a whitehead or pustule, or it may remain as a deeper red or tender bump beneath the skin.

Clue #3: Where is it?

Cold sores commonly occur on or around the border of the lips, although they can also occur around the nose and chin.

Pimples can appear close to the lips too, but they don't typically develop directly on the lip surface itself.

Clue #4: What happens next?

Cold sores tend to progress through stages:

Tingling → blistering → weeping → crusting → healing.

A pimple follows a different course and doesn't typically form the same cluster of fluid-filled blisters followed by a characteristic cold sore crust.

Whatever you do, don't pop it

If you think it might be a cold sore, definitely don't try to pop it.

Cold sores are contagious, and picking or popping can increase irritation, spread the virus to surrounding skin and potentially introduce bacteria.

And honestly? We don't recommend attacking pimples either.

What if I'm still not sure?

Don't diagnose yourself based solely on an internet article.

If you're unsure whether a lesion is a cold sore, pimple or something else, particularly if it's your first outbreak, painful, severe or unusual, speak with a doctor or pharmacist.