Causes of Cold Sores
Causes of cold sores are rooted in infection with the herpes simplex virus, most commonly HSV-1. Once a person is infected with HSV-1, the virus establishes a permanent presence in the body. Typically residing in the nerve ganglia near the spine. Cold sores develop when the virus becomes active and travels down nerve pathways to the skin’s surface, where it causes a blistering reaction.
The primary method of HSV-1 transmission is through direct skin-to-skin contact. Kissing, sharing utensils, or touching infected areas and then touching another person are all common ways the virus spreads. Infection is often contracted in childhood through non-sexual contact . With parents or other close relatives who may not even know they carry the virus.
After the initial infection, the virus enters a dormant stage. For reasons not fully understood, it can become reactivated at any time. Certain factors are known to trigger this reactivation, including:
- Emotional stress or fatigue
- Fever or illness
- Menstruation or hormonal changes
- Prolonged sun exposure or windburn
- Skin trauma or cosmetic procedures like lip fillers
Causes of Cold Sores
These triggers often weaken the immune system or create localised inflammation. Giving the virus an opportunity to resurface and cause a cold sore outbreak.
Although HSV-1 is most often responsible for oral cold sores. HSV-2, the virus commonly linked to genital herpes, can also cause oral infections, especially through oral-genital contact. In such cases, the infection may follow a similar pattern of recurrence.
Some individuals are more prone to frequent outbreaks due to genetic factors. An immune system that struggles to suppress viral activity. For those with compromised immune systems. Such as people undergoing chemotherapy, organ transplant recipients, or individuals living with HIV—the virus can cause more widespread or severe cold sores, requiring more aggressive treatment.
Causes of Cold Sores
In infants, HSV can cause dangerous infections, especially if acquired during birth or shortly after. For this reason, adults with active cold sores are advised to avoid kissing newborns or sharing close contact during outbreaks.
Ultimately, the causes of cold sores lie in initial HSV-1 infection. Followed by future reactivations triggered by internal or external factors. Understanding what triggers your outbreaks can help minimise their frequency and duration.[Next: Symptoms of Cold Sores →]
