The Bottom Line

Herpes simplex virus (HSV) causes cold sores (HSV-1) and genital herpes (HSV-2), two of the most common viral infections in the world. Over 70% of the global population carries HSV-1, and HSV-2 affects 15–20% of people in developed countries. While there is no cure, antiviral medications dramatically reduce the frequency, severity, and duration of outbreaks—and reduce the risk of passing the virus to a partner. Daily suppressive therapy can cut recurrences by 70–80%.

What Is Herpes Simplex Virus?

Herpes simplex virus (HSV) is a common virus with two types. HSV-1 primarily causes oral herpes—the familiar cold sore on the lip—while HSV-2 primarily causes genital herpes. However, both types can infect either location. Once you are infected, the virus stays in your body permanently, living dormant in nerve cells near the original infection site. It reactivates periodically—triggered by stress, illness, sunlight, or hormonal changes—producing recurrent outbreaks of blisters.

HSV is extremely common. More than 70% of the global population is seropositive (carries antibodies) for HSV-1, often from childhood exposure. HSV-2 seroprevalence is 15–20% in developed nations and up to 40–60% in developing countries. The majority of people with HSV have mild or no symptoms—but they can still transmit the virus to others through a process called asymptomatic shedding.

Signs and Symptoms

Primary (first-time) infection is often more severe than recurrences:

  • A prodrome (warning phase) of tingling, itching, or burning at the site that lasts 24–48 hours
  • Grouped blisters on a red base at the mouth (cold sores) or genitals
  • Blisters break open within 24–48 hours, leaving shallow, painful sores that crust over and heal in 7–14 days
  • Fever, swollen lymph nodes, muscle aches, and fatigue are more common in first infections
  • Oral HSV in children can cause gingivostomatitis—extensive painful ulcers throughout the mouth and gums, making eating very difficult

Recurrent outbreaks tend to be milder:

  • Shorter and less severe than the first outbreak—typically healing in 5–10 days
  • Fewer blisters (3–5 vs. 10–20 in a primary episode)
  • Located in the same area each time (e.g., always on the same part of the lip)
  • Prodromal tingling or burning recognized by about 80% of patients—this is the best time to start antiviral medication

Recurrence rates vary by type. HSV-2 recurs more often (4–5 times per year in the first year, declining over time) than HSV-1 (typically 1–2 times per year). About 30–40% of women with HSV-2 notice recurrences are tied to their menstrual cycle.

Causes and Transmission

HSV spreads through direct contact with the virus—either from an active blister or through asymptomatic shedding. Key transmission facts:

  • Asymptomatic shedding: HSV-2 sheds virus on 10–15% of days even without visible sores. This is how 60% of new infections are transmitted—from a partner with no visible outbreak.
  • Oral HSV-1: Spreads through saliva, kissing, or sharing utensils. Most people acquire it in childhood.
  • Genital HSV: Spreads through sexual contact. Condoms reduce (but do not eliminate) transmission risk. Suppressive antiviral therapy further reduces transmission by about 50%.
  • Recurrence triggers: Stress, illness, fever, UV sunlight exposure, menstruation, and immunosuppression can all reactivate the virus.

Treatment Options

There is no cure for HSV, but antiviral medications are highly effective at reducing the duration, severity, and frequency of outbreaks—and at lowering the risk of transmission.

For outbreaks (episodic treatment):

  • Starting antiviral medication as soon as you feel the prodromal tingling gives the best results—treatment started within 24 hours of symptoms can prevent full blister development.
  • Options include acyclovir, valacyclovir, and famciclovir in varying doses and durations (typically 3–10 days). Your dermatologist will recommend the right regimen.
  • For cold sores, topical antivirals (penciclovir cream or acyclovir cream) are available but are less effective than oral medications.

For frequent recurrences (suppressive therapy):

  • Daily oral antiviral medication (taken every day, not just during outbreaks) reduces recurrences by 70–80% and reduces asymptomatic viral shedding—lowering the risk of transmitting HSV to a partner by about 50%.
  • Suppressive therapy is generally recommended for anyone with 6 or more outbreaks per year, or for anyone with a partner who does not have HSV and wishes to reduce transmission risk.

For people with weakened immune systems:

  • Higher doses and sometimes IV acyclovir are needed, since HSV can cause more severe and prolonged outbreaks in immunocompromised patients.

In pregnancy:

  • Suppressive acyclovir or valacyclovir starting at 36 weeks of pregnancy reduces the risk of an active outbreak at delivery, lowering the need for cesarean section and the risk of neonatal herpes.

When to See a Dermatologist

  • You think you may have your first herpes outbreak—early antiviral treatment reduces severity
  • You are having frequent or severe recurrences (6 or more per year)
  • Your outbreaks are not responding to treatment or are taking longer than usual to heal
  • You have HSV and a partner who does not—a dermatologist or infectious disease specialist can guide suppressive therapy and transmission reduction strategies
  • You are pregnant and have genital herpes—delivery planning is important
  • You have any eye involvement (pain, redness, vision changes) with an outbreak—herpes keratitis can cause permanent corneal scarring
  • You are immunocompromised and having an HSV outbreak

Frequently Asked Questions

If I have no visible sores, can I still spread herpes?

Yes. This is one of the most important facts about HSV. Asymptomatic viral shedding means the virus is present on the skin or mucous membranes without any visible sores, and transmission can still occur. HSV-2 sheds asymptomatically on about 10–15% of days. This is why the majority of new herpes infections come from partners who did not know they had an active infection. Suppressive antiviral therapy and condom use together significantly reduce (though do not eliminate) this risk.

How do I know if I have HSV-1 or HSV-2?

Type-specific blood tests (HSV-1 IgG and HSV-2 IgG) can tell you which type you carry. This matters because HSV-2 tends to recur more frequently and is more often genitally located, while HSV-1 recurs less often. PCR testing of active blisters can also identify the type. Knowing your type helps your dermatologist guide treatment and discuss transmission risk accurately.

Does having herpes mean I will always have outbreaks?

Not necessarily. Recurrence frequency varies enormously—some people have frequent outbreaks, while others rarely or never have visible symptoms after the first episode. On average, HSV-2 recurrences decrease over time: from about 4–5 per year in the first year to near zero within 5 years for many people. Daily suppressive therapy can dramatically accelerate this process for people bothered by frequent outbreaks.

Can I have a normal relationship and sex life with herpes?

Yes. Millions of people with HSV have fulfilling relationships. Open communication with partners, understanding transmission risks, consistent condom use, suppressive antiviral therapy, and avoiding sexual contact during outbreaks can substantially reduce the risk of transmission. Many couples with one HSV-positive and one HSV-negative partner choose to use suppressive therapy to protect the uninfected partner.

References

  1. Looker KJ, et al. Global and regional estimates of prevalent and incident herpes simplex virus type 1 infections in 2012. PLOS ONE. 2015;10(10):e0140765.
  2. Corey L, et al. Once-daily valacyclovir to reduce the risk of transmission of genital herpes. N Engl J Med. 2004;350(1):11-20.
  3. Schiffer JT, Corey L. Herpes simplex virus. In: Mandell GL, et al., eds. Principles and Practice of Infectious Diseases. 8th ed. 2015.
  4. Workowski KA, Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recomm Rep. 2015;64(RR-03):1-137.

Trusted Resources

Always consult a board-certified dermatologist for diagnosis and personalized treatment recommendations.