There are two reasons behind blisters on lips. One is known as fever blisters, and the other is called the cold sores. Both of these conditions are caused by a virus known as the herpes simplex virus of the type of 1.
How is it caused?
This virus spreads quite easily because it can be transferred from one person to another person through the saliva. This can either happen directly or even by drinking water from one glass. Skin contact can also transmit this virus.
Once the person has been infected, then after that time, the virus stays inactive within the nerves present in the face. Then, in a few people, the virus becomes active again and again. When this takes place, cold sores start to appear. The virus that causes this cold sores is triggered by either a fever or a cold. These cold sores can also be caused due to an excess amount of stress; both emotional and mental stress. Blisters on lips are also caused by illness, sun exposure, trauma or dental treatment.
About cold sores:
Cold sores appear on the lips in the form of some small blisters. 80 percent of the people have the virus that is responsible for the cold sores. In fact, some people are infected even before they turn ten years old. Later, HSV-1 can be activated again in the body. Sometimes there might be no apparent reason for them to appear again. However, in some cases, it can be because of illness, exposure to sunlight, or poor exposure. In some cases, the virus might also be reactivated by any dental process that requires the dentist to stretch the lips.
Symptoms of the blisters:
Those people that are infected with the virus for the first time will probably have a headache, or fever. They might also feel nauseous. There is a high possibility of open sores and painful swellings to occur. For some people, the most common symptom is a sore throat. The symptoms mostly start to appear one week after the exposure of the virus.
The very first sign of the appearance of the cold sore is either an itching, a burning or a tingling. Then the second symptom is the appearance of redness and swelling. Then, within the next day or two days, either one or some small Blisters On Lips starting appear. These are referred to as fever blisters. Then, these blisters end up popping, and then they form painful sores which are called cold sores. Eventually, these sores start to get covered up with crusts which look a lot like scabs.
Where do the blisters appear?
These sores appear most commonly on the outlines of the lips. However, it is not rare for these blisters to appear on the inside of the mouth as well. The appearance of the blisters within the mouth is most common in those people that have any medical problem or have a weak immune system.