Cold sores, often called fever blisters, are clustered, small, fluid-filled blisters. You may feel a tingling on your lip before a small, hard, painful spot appears (top). In a day or two, blisters form, which later break and ooze (bottom). Healing usually occurs in two to three weeks without scarring.

How long does it take for a cold sore to appear?

The first sign of a cold sore is usually a tingling, burning, or itching sensation on or around the lips, beginning about 12-24 hours before the cold sore develops. The area becomes red, swollen and painful as the blisters form. Over 2-3 days, the blisters rupture and ooze fluid that is clear or slightly yellow.

Do cold sores show up right away?

Initial herpes symptoms usually show up 2 to 20 days after youre infected. But it may be years before the first symptoms appear. Herpes sores usually heal in a few weeks. But the virus stays in your body – and it can flare up and cause sores again.

Why did I randomly get a cold sore?

Cold sores are caused by the herpes simplex virus. Once this virus is in you, it can cause outbreaks of cold sores. Cold sore outbreaks are often triggered by exposure to hot sun, cold wind, a cold or other illness, a weak immune system, changing hormone levels, or even stress.