How HSV Actually Works

If you’ve been diagnosed with herpes, you may have questions about the virus and how it works. This article goes into detail about HSV, aka Herpes Simplex Virus, and what to expect if you have it. With more understanding, you can manage it better.

How HSV is contracted

Herpes spreads through direct skin-to-skin contact — specifically, contact with an area of skin where the virus is active. This can happen whether or not visible sores are present.

Oral HSV (most often HSV-1) is typically spread through kissing, oral-to-oral contact, or oral sex. Many people contract HSV-1 in childhood through normal family interactions, e.g. a kiss on the cheek or near the mouth from mom or a family member, etc.

Genital HSV (most often HSV-2, though HSV-1 can also cause genital outbreaks) is spread through genital-to-genital or oral-to-genital sexual contact.

In both cases, the point of entry determines where the virus settles. Oral contact leads to oral HSV; genital contact leads to genital HSV. Either type can establish itself in either location depending on the nature of the contact. However, oral HSV-2 is very rare.

What herpes does not spread through: toilet seats, towels, water, or casual contact like hugging or sharing a meal. The virus doesn’t survive outside the body and requires direct skin contact to pass between people.

One important nuance: most contractions happen when no visible symptoms are present (a phenomenon called asymptomatic shedding, covered in more detail below.)

How HSV Lives in the Body

Once herpes enters the body, it travels to a clusters of nerve cells: the trigeminal ganglia (near the base of the skull) for oral herpes, or the sacral ganglia (at the base of the spine) for genital HSV. There, the virus goes quiet and takes up lifetime residence.

In its quiet state, the virus isn’t replicating or causing symptoms; it’s just chilling in the nerve tissue. Herpes stays in the nerve tissue because the immune system has limited reach there.

Periodically, the herpes virus reactivates, traveling back down the nerve pathway to the skin surface. Sometimes that causes a visible outbreak, but usually it doesn’t. We call when the virus reactivates without any visible symptoms “asymptomatic shedding” or “silent shedding.”

Outbreak Timeline

Not everyone experiences outbreaks the same way, but there’s a consistent pattern.

The prodrome

Many people notice early signals before anything visible appears. These symptoms are usually felt near the area where the outbreak appears:

• Tingling, itching, or burning at the site
• Mild pressure or skin sensitivity in the area
• Fatigue, lower back ache, or generally feeling unwell (more common with genital HSV-2)

The prodrome typically lasts a few hours to a couple of days and becomes more recognizable over time. For most people it’s a reliable heads-up to start antiviral medicine now to reduce the duration and severity of the outbreak.

Active phase and timeline

The active phase of a recurrent outbreak typically runs 3–5 days; full healing usually completes within 7–10. Taking antiviral medicine shortens this window and makes the outbreak less severe.

First outbreak vs. recurrences

The first outbreak is often the worst. It’s often more painful, lasts longer and has more symptoms than the following outbreaks. The initial outbreak can last up to two weeks and sometimes people experience flu-like symptoms, including fever, body aches and headache, as the immune system mounts its initial response. Recurrent outbreaks tend to be shorter, milder, and more predictable. Many people experience fewer outbreaks over time; some people stop having noticeable outbreaks altogether, often in 1-2 years after initial infection.

What Outbreaks Look Like

Visible outbreaks tend to follow a typical pattern: redness and tenderness on the skin followed by small blisters. The blisters are usually clustered together, fluid-filled, and ranging from barely noticeable to many clusters. Over the next few days, the blisters break open and become open, tender sores. The sores crust over and heal gradually from the outer edges inward.

For oral herpes, blisters and sores often appear on or around the edge of the lips, the corners of the mouth, or the lower face. For genital herpes, sores typically appear on the genitals (penis or vaginal labia), inner thighs, or buttocks.

Severity varies. Some outbreaks are severe enough to be very painful; others are subtle enough to be mistaken for an ingrown hair or minor irritation.

Asymptomatic Shedding

Asymptomatic shedding is one of the most important things to understand, and one of the most confusing. Asymptomatic shedding is when the virus starts replicating and moves to the surface of the skin without causing visible symptoms. No sores, no prodrome, nothing you’d notice; yet, the virus can be passed to others during those moments. Experts believe this is how herpes frequently spreads and why it is such a common virus in the population. Many people spread it without knowing.

• Shedding tends to be more frequent in the first year after initial contraction, and decreases over time
• HSV-2 sheds more frequently than HSV-1, particularly in the genital region
• Daily antiviral medicine significantly reduces shedding — even on symptom free days

Not sure if you’ve been exposed? Understanding your testing options is a good place to start.

What HSV Is and Isn’t Linked To

A lot of health anxiety around herpes comes from things it isn’t actually connected to.

Cancer. HSV-1 and HSV-2 are often confused with HPV, but they’re completely different viruses. HPV is the one associated with certain cancers. HSV-1 and HSV-2 are not linked to cancer of any kind.

HIV. Having HSV-1 or HSV-2 doesn’t mean you have HIV, and one doesn’t cause the other. However, genital HSV-2 is associated with a higher chance of acquiring HIV if exposed due to the entry points that active sores create and ongoing inflammation between episodes. [Looker et al., 2017]

Infertility. Herpes has no established link to fertility complications for most people.

Newborn Herpes

HSV-1 and HSV-2 are an important cause of newborn herpes and sepsis which can be very serious.  About half of newborns who acquire herpes may die.  Mothers with genital herpes can spread infection to the newborn during birth.  Best to speak to your doctor about the risk of mother-to-child spread of herpes during pregnancy and delivery.  Antiviral medicine can reduce the spread of herpes from mothers to newborns.

The Alzheimer’s research

Over the past decade, research has examined whether HSV-1 may play a role in Alzheimer’s disease, because its presence in nerve tissue near the brain might contribute to the neuroinflammation associated with Alzheimer’s.

The latest findings show people who received antiviral treatment after an HSV-1 or HSV-2 diagnosis were significantly less likely to develop dementia than those who weren’t treated [Tzeng et al., Neurotherapeutics 2018]. However, this is observational correlated data, not a controlled trial. Clinical guidelines for treating HSV-1 haven’t changed. For those already on daily antivirals, there may be an incidental long-term benefit worth knowing about.

What This Means for You

Understanding how herpes behaves — dormancy, episodes, shedding — takes a lot of the uncertainty out of the picture. Episodes become something you can read, with their own early signals and a predictable timeline. Shedding becomes something you can actively reduce. The virus stays in nerve tissue, but your day-to-day life doesn’t have to revolve around it. Most people feel like they have more control once they understand this basic information.