Herpes simplex virus (HSV) is a common infection that can cause painful blisters or ulcers. There are two types of herpes simplex virus: type 1 (HSV-1) and type 2 (HSV-2). HSV-1 mostly spreads by oral contact and causes infections in or around the mouth (oral herpes or cold sores), but it can also cause genital herpes. HSV-2 spreads by sexual contact and causes genital herpes.

HSV primarily spreads by skin-to-skin contact, but it can also be transmitted through saliva, mucous membranes, or the oozing fluid from a sore. The virus can be spread even when the infected person has no sores or obvious signs of infection.

Most people have no symptoms or only mild symptoms, but the infection can cause painful blisters or ulcers that can recur over time. The symptoms usually begin within 2 to 20 days after contact with the HSV virus. The skin becomes painful or it may itch, burn or tingle. Then one or more blisters appear. The blisters open and become sores. The sores turn crusty and heal slowly over 1 to 2 weeks. By 3 weeks, the sores have completely healed without leaving a scar. Sometimes flu-like symptoms, such as swollen glands, headache, body aches and fever also develop.

HSV is treatable but not curable. Medicines can reduce symptoms but can’t cure the infection. During an outbreak, you may use an antiviral ointment or cream to help lessen your symptoms and help them go away faster, but it only works if you start it soon after you start an outbreak. Many people with HSV-2 take daily oral medications to keep outbreaks at bay.

You can reduce your risk of contracting HSV-1 by avoiding physical contact with the virus in sores, saliva, or surfaces in or around the mouth. You can reduce your risk of contracting HSV-2 by using condoms or dental dams during sexual activity.