If you ever notice a small blister forming around your mouth, it’s important to pay attention—it might be more than just a simple skin irritation. In fact, it could be a cold sore, also known as a fever blister, which is a very common viral infection caused primarily by the herpes simplex virus type 1, or HSV-1. While HSV-1 is the usual culprit, herpes simplex virus type 2 (HSV-2), which is more often linked with genital herpes, can also cause cold sores, especially when transmitted through oral-genital contact.

These sores are more than just an annoyance; they are highly contagious and can spread quickly from person to person through close contact. Cold sores are often transmitted through direct contact, such as kissing or sharing drinks, utensils, or food with someone who has an active outbreak. But it doesn’t stop there—indirect contact can also spread the virus. For example, if you use someone’s contaminated towel, lip balm, or even a piece of cutlery, you could easily become infected.

What’s more, people can reinfect themselves by touching a cold sore and then touching other parts of their body, like the eyes or genitals, a process known as autoinoculation. Recognizing the early signs of a cold sore can help you take action quickly. These sores often progress in stages. It usually starts with a tingling or itching sensation around the lips, nose, or mouth area, which can happen one to two days before the sore actually appears. Then, small fluid-filled blisters begin to form, typically near the lips, though they can also develop on the nose or gums. These blisters eventually break open and become painful red sores.

This stage is the most contagious and uncomfortable. After that, the sore begins to dry out, forming a scab that eventually falls off as it heals. The entire cycle of a cold sore outbreak usually lasts about seven to ten days. Even after the sore disappears, the virus doesn’t leave your body. Instead, it remains dormant and can be triggered again by certain factors. Several triggers can reactivate the virus and cause a new outbreak. Common triggers include emotional or physical stress, exposure to ultraviolet light or sunlight, hormonal changes such as those experienced during menstruation or pregnancy, and illnesses like the common cold or flu.

Additionally, people with weakened immune systems—whether due to medical treatments or chronic health conditions—are at greater risk for recurrent outbreaks. Although there’s currently no cure that can completely eliminate the herpes virus from your body, there are effective treatments available that can reduce the severity and duration of symptoms. Antiviral pills such as acyclovir, valacyclovir, and famciclovir are commonly prescribed and are most effective when taken at the first sign of an outbreak. There are also topical antiviral creams that can help reduce pain, itching, and the risk of spreading the virus to others. Over-the-counter medications like ibuprofen or acetaminophen can provide pain relief, and numbing creams can be applied to the affected area for additional comfort. Moisturizing balms and lip creams can also help reduce dryness and soothe irritated skin. Preventing cold sores—or at least minimizing their frequency—starts with a few practical habits. Avoid close contact with others when you have an active outbreak, and never share personal items like lip balm, towels, or eating utensils. If sun exposure is a known trigger for you, use a lip balm that contains sunscreen to protect your lips from UV rays. Supporting your immune system with a balanced diet, regular exercise, adequate sleep, and effective stress management is also crucial in keeping outbreaks at bay. If your cold sores occur frequently, become unusually painful, or don’t respond to over-the-counter treatments, it’s best to speak with a healthcare professional. They can help identify whether there’s an underlying health issue and recommend stronger prescription treatments if needed. While cold sores are common and manageable, understanding the causes, symptoms, and ways to treat and prevent them can make a big difference in your daily comfort and long-term health.