Cold sores occur in the form of tiny blisters that can appear around the lips or even in the chin area. This is primarily caused when the person is infected with the herpes simplex virus. These sores are also termed as fever blisters, and the infection can be recurring in some people. There are no permanent cures for this condition. Understating what causes cold sores can help in preventing the risk factors.

1. Direct transmission of HSV
There are two types of herpes simplex viruses that cause infection: HSV1 and HSV2 – the former causes cold sores and fever blisters while the latter is the reason behind herpes infections. But both these viruses when transmitted through kissing can result in sores around the mouth.

2. Viral infection triggers
People who had acquired the virus in their childhood might often not experience any significant symptoms. But the infection can be flared up due to a variety of triggers like viral fever or other kinds of viral infections in the later stages in life.

3. Stress
Stress can be the cause of a number of serious health problems and cold sores can be one among them. People who have never known that they have been carrying the herpes simplex virus in their bloodstream might suddenly suffer from bad cold sores if they do not keep tabs on their stress levels.

4. Hormone fluctuations
Various diseases, medications, and general health conditions can lead to fluctuations in hormone levels. Women, in particular, might notice the effects of triggering the dormant herpes simplex virus in their blood while approaching their periods. This is the time when there are several hormonal changes that can activate the virus and thus cause blisters.

5. Immunity problems
There are two common immune system-related issues — one is when the immune system is weakened due to external factors and the other is where there is an autoimmune disease. Both these conditions can be bad for people who are carrying the HSV1 virus in their nerve cells close to the lips. When the immune system gets weak, the dormant virus can cause the flare-up of bad sores around the mouth or even in the nose region.

6. Cosmetic procedures
One of the common ways in which herpes viruses can be transmitted besides direct transmission through kissing would be through cosmetic procedures. The use of unsterilized needles and other equipment used in cosmetic treatment is what causes cold sores in this case. The effects can be noticed immediately or the dormant virus might be triggered due to one of the above factors.

Though cold sores can be chronic infections in most cases, it would be helpful to know its causes. As the condition spreads easily, knowing about the causes and modes of transmission can help in preventing the problem from worsening.