You probably already have herpes. Here’s what you need to know

Written by:

Dr Tan Kok Kuan

Dr Tan Kok Kuan

Dr Tan is a medical doctor in private practice focusing on men's health, and a contributing author of the Singapore HIV PrEP prescribing guidelines and the Blueprint to end AIDS and HIV transmission in Singapore by 2030. Read more of his articles at


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Herpes, or the Herpes Simplex Virus (HSV), is one of the most common sexually transmitted diseases in the world. It’s so common that some estimates show up to 30% of the global population carry the virus. Let’s break it down for you.

So what’s herpes?

It’s a virus. It’s very contagious and most commonly spread via direct skin contact with infectious lesions on the skin. These can be blisters and ulcers. However, people who carry herpes can also shed the virus from normal skin that does not have any blisters or ulcers. That’s why it’s often spread via sexual contact and kissing, making herpes one of the most common STDs in the world.

Once Herpes infects a person, it goes into hiding inside the nerve bodies and can never be fully eradicated from the body. However, even though it lives in the body, it does not cause any harm except for occasionally causing troublesome skin symptoms. These symptoms resolve with or without treatment.  

What are the signs and symptoms of herpes infections?

Herpes infections switch between two phases: (1) An acute (flare) phase characterised by painful blisters and ulcers on the skin; and (2) a chronic (latent) phase in which the patient feels perfectly well and symptom-free.

Acute phase

In an acute or flare phase, blisters filled with the HSV virus appear on the skin. These blisters are surrounded by a ring of inflamed red skin earning them the very romantic description of “dew drops on a rose petal”.

The commonest affected sites are around the mouth and genitals. Left untreated, these blisters usually dry up over three to four weeks. However, this is when you are most infectious. When the blisters break, the fluid containing HSV can infect people who come into direct contact with it. As the blisters rupture, they become painful open sores. These sores can also become infected with bacteria, further complicating recovery.

You will continue to be infectious as the lesions heal because the virus is still present on your skin during the healing process. This means that until the blisters or sores dry up, you are still infectious and “shedding” virus. Only until the skin is in the state where it was before the blisters can the acute phase be considered to be over. Condoms do give some protection to your partner but because it may not cover all the lesions, your partner may still get infected.

Therefore, my advice to my patients during an acute flare is

  • Prompt treatment
  • Take care not to let anyone come into contact with the blisters/sores
  • Do not share towels
  • Abstain from sexual activity for at least three weeks or until the blisters have completely healed

Latent phase

In the chronic or latent phase, the HSV virus remains in your system and does nothing. You feel completely normal during this phase. Like having shingles after you have had chickenpox, it is not possible to predict when a HSV infection changes from a latent phase to an acute phase.

Some patients have a long latent phase lasting years while others have recurrent acute phases every one – two months. The usual natural history is for the frequency of flares to reduce with time. In the first 12 months following infection with Herpes, the flare frequency is on average every 1 to 2 months. This reduces to once in three to four months in the next 12 months. And continues to reduce until the patient reaches a stable phase. For most patients, this means a flare about once a year.

Situations that weaken the immune system also put the patient at risk of getting a herpes flare. For example falling ill with another illness, even the common cold. Or taking medicines that weaken the immune system like steroids. Or even many sleepless nights.

A person who carries herpes is still infectious during the latent phase. This is due to asymptomatic viral shedding. This means the person will continue to shed the herpes virus from the skin while not showing any signs or symptoms and feeling completely well. Albeit the level of infectivity during the latent phase is much much lower compared to the flare phase.

How do I get tested for herpes?

There are two ways to test for HSV: A blood test, and a swab test of blisters or ulcers.

How do you treat herpes?

Herpes is not curable. Once a patient has been infected, he will carry the virus in his body for the rest of his life. That said, not everyone with herpes needs to be treated.

There are people who live with herpes who have very infrequent flares. Or who have flares so mild that even without treatment, goes away in a few days and does not bother the patient. Many people choose not to actively treat the herpes flares and this is perfectly OK.

Anti-viral medicines are the mainstay of herpes treatment. There are anti-viral tablets and anti-viral creams. There are two strategies to treat herpes: ad-hoc and suppressive. The suppressive treatment is not meant to cure the virus but to reduce the chance of a recurrence.

In conclusion

HSV is a very common virus and remains in the body for life. Aside from occasional acute flares of the infection, there are minimal long-term side effects of the infection. The most important thing to do is to seek medical advice early, arrive at a diagnosis, and plan how best to manage flares when they come.