Also called: HSV
Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Herpes Simplex
Herpes is an infection that is caused by a herpes simplex virus (HSV). Oral herpes causes cold sores around the mouth or face. Genital herpes affects the genitals, buttocks or anal area. Genital herpes is a sexually transmitted infection (STI). It affects the genitals, buttocks or anal area. Other herpes infections can affect the eyes, skin, or other parts of the body. The virus can be dangerous in newborn babies or in people with weak immune systems.
There are two types of HSV:
- HSV type 1 most commonly causes cold sores. It can also cause genital herpes.
- HSV type 2 is the usual cause of genital herpes, but it also can infect the mouth.
HSV spreads through direct contact. Some people have no symptoms. Others get sores near the area where the virus has entered the body. They turn into blisters, become itchy and painful, and then heal.
Most people have outbreaks several times a year. Over time, you get them less often. Medicines to help your body fight the virus can help lessen symptoms and decrease outbreaks.
It sits within Infections, Mouth and Teeth, Sexual Health Issues, Female Reproductive System and Male Reproductive System.
The lead U.S. institute for this subject is the National Institute of Allergy and Infectious Diseases.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Herpes Simplex
687 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- Engineered HSV-1 M032 for the Treatment of Children and Adults With Newly Diagnosed Diffuse Midline Glioma After Standard of Care RadiationM.D. Anderson Cancer Center
- Safety and Immunogenicity of Recombinant Varicella Zoster Virus Vaccine in People With HIV Who Have a CD4 Count Less Than 300 or Greater Than or Equal to 300 and a Healthy Control PopulationNational Institute of Allergy and Infectious Diseases (NIAID)
- Midpoint Transverse Process to Pleura (MTP) Block vs Erector Spinae Plane (ESP) Block for Acute Herpes Zoster (HZ) PainTanta University
- HSV G207 in Children With Recurrent or Refractory Cerebellar Brain TumorsM.D. Anderson Cancer Center
- Genetic Studies of Chronic Active Epstein-Barr DiseaseNational Institute of Allergy and Infectious Diseases (NIAID)
- Virotherapy and Natural History Study of KHSV-Associated Multricentric Castleman s Disease With Correlates of Disease ActivityNational Cancer Institute (NCI)
Research already completed
- Herpesviruses Reactivation In Hiv-Infected Women Initiating ART (HERA)National Institute of Allergy and Infectious Diseases (NIAID)
- Study of the Safety of a Particular Herpes Vaccine in Adults With or Without Herpes InfectionNational Institute of Allergy and Infectious Diseases (NIAID)
- Neonatal Phase 1 Valacyclovir StudyNational Institute of Allergy and Infectious Diseases (NIAID)
- Trial on Efficacy and Safety of Pritelivir Tablets for Treatment of Acyclovir-resistant Mucocutaneous HSV (Herpes Simplex Virus) Infections in Immunocompromised SubjectsAiCuris Anti-infective Cures AG
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- Herpes Can Happen to Anyone: Share Facts, Not FearsNational Institutes of Health
- Herpes Simplex: OverviewAmerican Academy of Dermatology
Diagnosis and Tests
- Herpes (HSV) TestNational Library of Medicine
Related Issues
- Herpes Eye DiseaseAmerican Association for Pediatric Ophthalmology and Strabismus
Clinical Trials
- ClinicalTrials.gov: Herpes SimplexNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Herpes Simplex. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Herpes Simplex, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.