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Sexually transmitted infections (STIs) can silently impact male fertility. Often symptomless, these infections can damage sperm, block reproductive pathways or reduce hormone levels, sometimes before you even realise they are present. In this article, we’ll look at seven STIs that affect male fertility, how they cause harm, and how you can protect your future.
Table of Contents
STI Symptoms in men
Sexually transmitted infections (STIs) in men can present with a range of symptoms, but many cases remain silent until complications arise. Recognizing the early warning signs is important for protecting both reproductive health and fertility.
Common symptoms in men include:
- Genital: sores, blisters, warts, unusual growths, itching/redness, testicular pain or swelling, painful ejaculation.
- Urinary: burning or pain when urinating, frequent urination, penile discharge (clear, white, yellow, green), occasional bleeding.
- Rectal: itching, pain, discharge, bleeding, painful bowel movements.
- Oral/Throat: sore throat, redness, oral sores or lesions.
- Systemic: fever, fatigue, swollen lymph nodes, body aches, rash (palms/soles), nausea/vomiting, abdominal pain, jaundice, hair loss or neurological issues (in late untreated cases).
Important note: Many STIs in men cause no symptoms at all, especially in the early stages. This makes routine screening and prompt medical attention critical, even if no obvious signs are present.
Source: Brito, J., 2020
7 STIs that affect male fertility
| STI | Impact on Male Fertility |
| Chlamydia, Gonorrhea, Syphilis | In men, chlamydia, gonorrhea and syphilis can infect the urinary and reproductive tracts (epididymitis), causing inflammation and scarring that block sperm movement. It can also directly damage sperm by reducing their quality, motility, and DNA integrity.Untreated syphilis can specifically damage nerves over time, leading to erectile dysfunction. |
| Human Papillomavirus (HPV) | Some types of HPV can cause a persistent infection that can progress to genital cancers, which can affect fertility. |
| Herpes Simplex Virus (HSV) | HSV may lower sperm count, reduce motility, damage sperm, and cause prostate inflammation. It can also be passed through sperm, increasing miscarriage risk. |
| HIV/AIDS | HIV can harm male fertility by reducing sperm motility, lowering semen volume, and making semen thicker. These changes may be caused by the virus itself or side effects of HIV treatment. |
| Trichomoniasis | Trichomoniasis reduces male fertility by releasing proteins that decrease sperm survival and motility, damage the ‘cap’ on the sperm head and cause sperm cell death. These effects reduce semen quality, limiting fertilisation and disrupting early embryo development. |
Sources: Cunningham K. A., et al., 2008; Loma Linda University, n.d.; Dabizzi, S., et al. 2024; Zhang, Z., Li, F., et al. 2023; Goulart, A. C. X., et al. 2020
Men with fertility problems caused by STIs usually experience these issues when the infection is left untreated or becomes persistent over time. Chronic or repeated inflammation can result in lasting damage. By contrast, early infections that are promptly detected and treated often resolve without causing any permanent effects. This is why routine testing, early diagnosis and timely treatment are essential in preventing fertility complications.
STI Treatment
While several STIs can harm male fertility, treatment options vary; some are fully curable, while others can only be managed to reduce their long-term impact. Some treatment options include:
- Antibiotics (Chlamydia, Gonorrhea, Syphilis, Trichomoniasis)
- Antivirals (HSV)
- Vaccination & wart removal (HPV)
- Antiretroviral therapy / ART (HIV/AIDS)
Some STIs that affect male fertility are curable, while others can only be managed. Bacterial and parasitic infections like chlamydia, gonorrhea, syphilis, and trichomoniasis can usually be cured with timely treatment, preventing lasting damage. Viral infections such as HPV, herpes, and HIV cannot be cured, but vaccines and antiviral therapies help control their impact on fertility and overall health.
Source: WHO, 2025
STI Prevention
- Use condoms consistently and correctly
- Limit number of sexual partners
- Get tested regularly and encourage partner testing
- Complete full STI treatments to avoid reinfection
- Get vaccinated (HPV, Hepatitis B)
- Avoid sharing needles or personal items that may transmit infections
- Maintain open communication with partners about sexual health
Source: CDC, 2024
Homed-IQ offers discreet and reliable at-home STI testing kits, enabling you to monitor your sexual health from the comfort of your own home. The process is simple: order a test online, collect your sample at home following the clear instructions provided and send it to a certified laboratory using the pre-paid envelope provided. The laboratory will analyse your sample, and you will receive the results securely online, often within a few days.
Summary
The fertility of men can be seriously affected by seven major sexually transmitted infections (STIs): chlamydia, gonorrhoea, syphilis, human papillomavirus (HPV), herpes, HIV and trichomoniasis. These infections can harm reproductive health in various ways, including blocking sperm ducts, reducing sperm motility, damaging DNA, and lowering hormone levels. While some, such as chlamydia and gonorrhoea, are curable if treated early, others, including HPV, herpes and HIV, can only be managed. Recognising these risks emphasises the importance of raising awareness, encouraging testing and promoting prevention to protect fertility and long-term health.
References
Brito, J. (2020, October 20). 8 sperm myths and facts. Medical News Today. Retrieved August 18, 2025, from https://www.medicalnewstoday.com/articles/sperm-facts#sperm-myths
CDC. (2024, April 9). How to Prevent STIs | STI. CDC. Retrieved August 18, 2025, from https://www.cdc.gov/sti/prevention/index.html
Cunningham, K. A., & Beagley, K. W. (2008). Male genital tract chlamydial infection: implications for pathology and infertility. Biology of reproduction, 79(2), 180–189. https://doi.org/10.1095/biolreprod.108.067835
Dabizzi, S., Maggi, M., & Torcia, M. G. (2024). Update on known and emergent viruses affecting human male genital tract and fertility. Basic and clinical andrology, 34(1), 6. https://doi.org/10.1186/s12610-024-00222-5
Goulart, A. C. X., Farnezi, H. C. M., França, J. P. B. M., Santos, A. D., Ramos, M. G., & Penna, M. L. F. (2020). HIV, HPV and Chlamydia trachomatis: impacts on male fertility. JBRA assisted reproduction, 24(4), 492–497. https://doi.org/10.5935/1518-0557.20200020
Loma Linda University. (n.d.). STDs Affecting Fertility | Loma Linda Univ. Fertility & IVF | CA. Loma Linda Fertility. Retrieved August 18, 2025, from https://lomalindafertility.com/infertility/stds-and-infertility/
Torgovnik, J. (2025, May 29). Sexually transmitted infections (STIs). World Health Organization (WHO). Retrieved August 18, 2025, from https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)
Zhang, Z., Li, F., Deng, Y., Li, Y., Sheng, W., Tian, X., … & Mei, X. (2023). Trichomonas vaginalis excretory secretory proteins reduce semen quality and male fertility. Acta Tropica, 238, 106794.
