If something painful and blister-like suddenly appears around your mouth, it’s important not to ignore it—it could be a cold sore, a sign that you’ve been infected with the herpes simplex virus. Cold sores, often referred to as fever blisters, are caused most commonly by herpes simplex virus type 1 (HSV-1).

However, in some cases, herpes simplex virus type 2 (HSV-2)—which is typically associated with genital herpes—can also cause cold sores, especially through oral-genital contact. These small but uncomfortable sores are a widespread viral infection, and they can appear on or around the lips, the nose, or even inside the mouth. Cold sores are extremely contagious and can be spread easily from one person to another, especially through direct contact like kissing or sharing drinks, utensils, or food with someone who is currently experiencing an outbreak.

The virus can also be transmitted through indirect contact by using contaminated objects such as towels, lip balm, or even eating utensils. In some cases, individuals can spread the virus to different areas of their own body, such as the eyes or genitals, by touching an active sore and then touching another part of the body—a process known as autoinoculation. Recognizing the early signs of a cold sore is essential to managing the condition effectively. The first symptom most people experience is a tingling, itching, or burning feeling in the area where the sore will appear, usually a day or two before any visible symptoms.

This is followed by the formation of small, fluid-filled blisters that typically appear near the lips but can also develop on the nose, cheeks, or inside the mouth. These blisters eventually break open, leaving behind painful red sores, which is the most contagious stage of the outbreak. After this, the sores dry out, scab over, and begin the healing process, which usually takes about 7 to 10 days from start to finish. Once the sores have healed, the virus doesn’t go away—it remains dormant in the body and can be reactivated later on. Several different triggers can cause a dormant virus to become active again and lead to another outbreak.

Common triggers include physical or emotional stress, exposure to sunlight or ultraviolet rays, hormonal changes such as those during menstruation or pregnancy, illnesses like colds or fevers, and having a weakened immune system due to health conditions or medical treatments. While there’s currently no cure that can completely eliminate the herpes virus from the body, there are effective treatments that can help reduce the severity and duration of symptoms. Prescription antiviral medications like acyclovir, valacyclovir, or famciclovir can be taken in pill form and are especially effective if started early in the outbreak. These medications help control the virus and speed up the healing process. There are also topical antiviral creams that can be applied directly to the sore to ease discomfort and potentially limit the spread of the virus. Over-the-counter pain relievers such as ibuprofen or acetaminophen can help manage pain, while numbing creams and soothing lip balms can relieve dryness and irritation. Preventing the spread of cold sores and reducing the chances of future outbreaks involves a few key steps. Avoid kissing or engaging in close contact with others during an active outbreak, and don’t share personal items like lip balm, towels, or utensils. If sunlight is a known trigger for you, consider using a lip balm that contains sunscreen to protect your lips from UV exposure. It’s also important to support your immune system by maintaining a healthy diet, staying active, getting enough rest, and managing stress. If you find that cold sore outbreaks are happening more frequently than usual, are particularly painful, or don’t seem to respond to over-the-counter remedies, it’s a smart idea to see a healthcare provider. They can help determine whether you need prescription medication or if there’s another underlying condition that needs to be addressed. Although cold sores are common and often harmless, they’re still a clear sign that your body is dealing with a viral infection, and understanding how to treat and prevent them can make a big difference in both your comfort and overall health.