Herpes causes painful sores and blisters that come and go over time, but for most people, the physical effects are mild and become less frequent with each passing year. The virus itself never leaves your body. After the first outbreak, it retreats into nerve cells and stays dormant until something triggers it to reactivate. Around 846 million people aged 15 to 49 worldwide are living with genital herpes, making it one of the most common infections on the planet.
What herpes does to you depends on the type of virus, where it infects you, and how your immune system responds. Here’s what actually happens in your body.
The Two Types of Herpes Simplex Virus
HSV-1 and HSV-2 are closely related but behave differently. HSV-1 traditionally causes oral herpes (cold sores around the mouth), though it increasingly causes genital infections too. HSV-2 almost exclusively affects the genital area. Globally, about 520 million people have genital HSV-2, while another 376 million have genital HSV-1. You can carry both types simultaneously.
Both types follow the same basic pattern: infect, retreat, reactivate. The difference is mainly in how often they flare up and where on the body they prefer to live.
What the First Outbreak Feels Like
The initial herpes outbreak is typically the worst one you’ll experience. It lasts 2 to 4 weeks and can feel like a combination of flu-like illness and localized pain. You may notice fever, body aches, and swollen lymph nodes alongside the sores themselves.
The sores start as small, fluid-filled blisters around the lips, genitals, or anus. Over several days, these blisters break open, release fluid, and form shallow ulcers. They then crust over and heal without leaving scars. If sores are on the genitals, a stinging or burning sensation during urination is common. Some people also feel tingling or itching in the area before sores appear, a warning sign known as the prodrome.
Not everyone gets a noticeable first outbreak. Some people carry the virus for years without ever developing visible sores, which is one reason herpes spreads so effectively.
How the Virus Lives in Your Body
After the initial infection, herpes travels along nerve fibers and settles into clusters of nerve cells near the base of the spine (for genital herpes) or near the ear (for oral herpes). There, it enters a dormant phase where it essentially hides from your immune system. The virus isn’t replicating or causing symptoms during this time, but it’s permanently embedded in those nerve cells. Your body cannot clear it.
Periodically, the virus reactivates and travels back along the nerve to the skin surface. This can produce a visible outbreak, or it can happen invisibly. Triggers for reactivation vary from person to person but commonly include stress, illness, fatigue, sun exposure, hormonal changes, and friction or irritation in the affected area.
Recurrent Outbreaks Over Time
After the first episode, subsequent outbreaks are usually shorter, less painful, and less frequent. A recurrence typically lasts a few days to about a week rather than the 2 to 4 weeks of the initial outbreak. HSV-2 tends to recur more often than HSV-1 in the genital area, sometimes several times a year in the first couple of years after infection.
The good news is that outbreak frequency generally decreases over time. Many people find that after the first year or two, recurrences become rare or stop entirely. Your immune system builds a stronger response to the virus with each episode, keeping it suppressed more effectively.
Spreading Without Symptoms
One of the more consequential things herpes does is shed virus from the skin even when no sores are visible. This is called asymptomatic shedding, and it’s how many new infections are transmitted. Studies of people with HSV-2 found that the virus was present on the skin surface on roughly 3% of days when no sores were apparent. People with a known history of genital herpes shed at a similar rate, about 2.7% of days.
That percentage sounds small, but it adds up over months and years of sexual activity. It’s the primary reason herpes is so widespread despite many carriers never seeing a sore.
Effects on the Immune System
Herpes doesn’t just sit quietly between outbreaks. HSV-2 infection increases the risk of acquiring HIV two- to threefold. The virus creates microscopic breaks in the skin and mucous membranes, even during asymptomatic shedding, that make it easier for other infections to enter the body. It also attracts immune cells to the genital area that HIV specifically targets, creating a biological doorway.
Rare but Serious Complications
For most people, herpes remains a manageable skin condition. In rare cases, however, the virus can cause more serious problems.
Eye Infections
HSV keratitis is a herpes infection of the cornea, the clear front surface of the eye. Symptoms include eye pain, redness, blurred vision, sensitivity to light, and watery discharge. The infection usually heals without permanent damage, but repeated episodes or severe cases can scar the cornea. HSV keratitis is a major cause of blindness worldwide, though surgery for vision problems from scarring is rarely needed.
Brain Inflammation
Herpes encephalitis occurs when the virus reaches the brain, causing dangerous swelling. This is extremely rare but is a medical emergency. Symptoms come on quickly and include high fever, confusion, seizures, and difficulty speaking. Without treatment, it can be fatal or cause lasting neurological damage.
Newborn Infections
Herpes poses a genuine risk during pregnancy, particularly if a mother acquires a new infection in the third trimester. Neonatal herpes can affect a newborn’s skin, eyes, mouth, or in severe cases, the brain and internal organs. To reduce this risk, pregnant women with a history of herpes are given antiviral medication during the last month of pregnancy to prevent an active outbreak at delivery. If sores are present when labor begins, a cesarean delivery is recommended. Women who contract genital herpes for the first time in the third trimester may also be offered a cesarean because viral shedding can last longer with a new infection.
How Herpes Is Detected
If you have active sores, a swab test can identify the virus directly. When no sores are present, a blood test can detect antibodies your immune system has built against HSV. The catch is timing: after exposure, it can take up to 16 weeks or more for current blood tests to detect the infection. A test taken too soon after exposure may come back negative even if you’re infected.
Routine herpes screening isn’t standard practice in most settings, partly because the blood tests can produce false positives and partly because a positive result in someone without symptoms doesn’t always change medical management. Testing is most useful when you have symptoms, a known exposure, or a specific reason to check your status.
Managing Herpes Long-Term
Antiviral medications don’t cure herpes, but they meaningfully reduce how often outbreaks happen, how long they last, and how likely you are to transmit the virus. There are two main approaches.
Episodic therapy means taking medication at the first sign of an outbreak. You keep a prescription on hand and start it when you feel the tingling or notice a sore developing. A short course of a few days can shorten the episode significantly.
Suppressive therapy means taking a low dose of antiviral medication every day, whether or not you have symptoms. This approach reduces outbreak frequency by 70% to 80% in many people and also cuts the rate of asymptomatic shedding, lowering the chance of passing the virus to a partner. People with frequent recurrences (roughly six or more per year) often find daily suppressive therapy makes the biggest difference in quality of life.
Beyond medication, practical steps like getting enough sleep, managing stress, and avoiding known personal triggers can help keep the virus dormant for longer stretches. Using condoms and avoiding sexual contact during active outbreaks reduces transmission risk, though neither eliminates it completely because of asymptomatic shedding.