These sores, also known as fever blisters, are small swollen blisters that are filled with fluid and appear on the lips, mouth and nostrils.
These sores can be very painful and itchy, and last for several days (even up to seven weeks!).
Many people confuse these sores with canker sores.
But these two are really different as you will discover when you read about the signs of cold sores below: Cold sores are caused by a virus called herpes simplex type 1.
These sores are not dangerous but are highly contagious.
You will know this because it is a small blister on the lips or around the mouth, and the affected area is usually red, swollen and sore.
The sore is filled with clear fluid, and in time will break open and then leave a scab after several days.
On the first viral infection, you may experience either severe symptoms or no indication of symptoms at all.
For some, the first virus attack is coupled with a fever (this is why it these sores are also called fever blisters), swollen glands and bleeding gums.
Others have gingivostomatitis as signs of cold sores, wherein many painful sores appear around the mouth.
Some people experience what they call a prodrome - symptoms before the actual manifestation of the sores.
Prodrome includes tingling/stinging sensation along with the burning feeling on the area where the sores will appear after a few hours or may be a day or two.
These symptoms typically last for a few days, and the sores completely heal within two to seven weeks.
And it's a good thing that these sores are healed leaving no scars behind.
The manifestation of the signs of cold sores discussed above varies from person to person.
You should keep watch for all those signs so that you can use an effective medication at an early stage.
Most, if not all, medications for these sores show best results when implemented at the first show of symptoms.