Herpes (Herpes Simplex Virus)

Overview

Herpes is a very common infection caused by the herpes simplex virus (HSV). There are two main types: HSV-1, which usually causes cold sores (fever blisters) around the mouth, and HSV-2, which usually causes genital herpes. However, either type can affect either area, especially with oral-genital contact.

Once a person is infected, the virus stays in the body for life, remaining dormant in nerve cells and reactivating from time to time to cause outbreaks. Many people with herpes have very mild symptoms or none at all and may not know they are infected. While there is no cure, herpes is a manageable condition, and medications can reduce symptoms, shorten outbreaks, and lower the chance of spreading the virus to others.

Symptoms

Symptoms vary widely; some people have frequent outbreaks while others have none. A first outbreak is often the most severe and may include:

• Tingling, itching, or burning before sores appear
• Small painful blisters that break open and form sores or scabs
• Cold sores on or around the lips and mouth (oral herpes)
• Blisters or sores on the genitals, buttocks, or surrounding skin (genital herpes)
• Flu-like symptoms during a first outbreak, such as fever, body aches, and swollen lymph nodes
• Pain or burning during urination if sores are near the urinary opening

Later outbreaks are usually milder and shorter. Sores typically heal within one to two weeks. Seek prompt care if sores are severe, near the eyes, or occur with a weakened immune system.

Causes

Herpes is caused by the herpes simplex virus and spreads through close contact with an infected person, including when they have no visible sores. Transmission can occur through:

• Skin-to-skin contact with a cold sore or genital sore
• Kissing or sharing items such as utensils or lip balm (mainly HSV-1)
• Oral, vaginal, or anal sex (mainly HSV-2, and HSV-1 through oral sex)
• From parent to baby during childbirth, which can be serious for the newborn

The virus is most contagious during an outbreak but can also spread between outbreaks through "asymptomatic shedding," when the virus is present on the skin without symptoms.

Risk Factors

Factors that increase the risk of getting or spreading herpes include:

• Having unprotected sexual contact or multiple partners (for genital herpes)
• Close contact with someone who has an active cold sore
• A weakened immune system, which can lead to more frequent or severe outbreaks
• Being a newborn whose parent has active genital herpes at delivery

Common triggers that can reactivate the dormant virus and bring on an outbreak include stress, illness, fatigue, sun exposure (for cold sores), hormonal changes, and a weakened immune system.

Diagnosis

Herpes is often recognized by the appearance of typical sores during an examination. To confirm the diagnosis, a clinician may:

• Take a swab from a sore to test for the virus, which is the most accurate method when sores are present
• Order a blood test that detects antibodies to HSV, which can indicate past infection even without current sores
• Distinguish between HSV-1 and HSV-2 when relevant

Testing is especially helpful for confirming genital herpes, guiding counseling, and informing decisions during pregnancy. Because antibody tests have limitations, results are interpreted alongside symptoms and history.

Treatment

There is no cure for herpes, but treatment effectively controls symptoms and reduces transmission. Options include:

• Antiviral medications: Drugs such as acyclovir, valacyclovir, and famciclovir taken to treat outbreaks, ease pain, and speed healing.
• Suppressive therapy: Daily antiviral medication for people with frequent outbreaks, which reduces the number of outbreaks and lowers the risk of passing the virus to a partner.
• Symptom relief: Pain relievers, keeping sores clean and dry, and topical measures for comfort.
• Care in pregnancy: Special management to reduce the risk of passing herpes to the baby, sometimes including antiviral medication late in pregnancy and delivery planning.

Starting antiviral treatment early in an outbreak, ideally at the first signs, works best.

Prevention

You can lower the risk of getting or spreading herpes by:

• Avoiding skin-to-skin and sexual contact during an outbreak
• Using condoms or dental dams, which reduce but do not eliminate the risk of genital herpes
• Not sharing items like utensils, towels, or lip balm during a cold sore
• Taking daily suppressive antiviral medication if recommended, to reduce transmission to a partner
• Washing hands and avoiding touching sores, then the eyes
• Telling sexual partners and discussing testing and prevention

Pregnant people with herpes should inform their provider so steps can be taken to protect the baby.

When to See a Doctor

See a healthcare provider if you have your first suspected herpes outbreak, frequent or severe outbreaks, or sores that are slow to heal, so you can confirm the diagnosis and discuss treatment. Genital symptoms should be evaluated to distinguish herpes from other infections.

Seek urgent care if sores appear near or in the eye (which can threaten vision), if you have a weakened immune system with an outbreak, or if symptoms are severe. Pregnant people with herpes, or those whose partner has herpes, should tell their provider so the newborn can be protected, as neonatal herpes is serious.

Related Topics

Frequently Asked Questions

References

1. Centers for Disease Control and Prevention (CDC).
2. World Health Organization (WHO).
3. MedlinePlus, U.S. National Library of Medicine.