Can STI Symptoms Occur Within 48 Hours?

Every STI has a different incubation period. The incubation period is the time between the moment of infection and when symptoms first appear. Knowing the incubation period of different STIs is helpful when determining if the symptoms you may be experiencing are due to an STI or not. Many people wonder if symptoms of an STI can occur one or two days after having sex. In this article we will discuss how quickly symptoms of certain STIs can occur, what symptoms to watch out for, and when to get tested.

---

Table of Contents

• Common STI symptoms
• How quickly can STI symptoms appear?
• Window periods for STI Testing
• STI incubation periods
• STIs without symptoms
• Getting tested for STIs
• Prevention Tips
• Summary

---

Common STI symptoms

Many STIs cause similar symptoms following an infection that signal something isn’t right. Common STI symptoms are:

• Itching in the vagina, penis or anus. 
• Blisters and sores
• Discharge that has changed in colour, quantity, or has an unpleasant smell
• Fever
• Burning or redness in the genital or throat area such as the tongue

Keep in mind: The absence of symptoms does not mean the absence of infection. Many people with an STI feel completely healthy.

Source: NHS, 2022

If you are in doubt whether your symptoms are from an STI, getting tested is always a good idea. Homed-IQ’s STI Test Complete checks for 5 common STIs and can be done from home.

How quickly can symptoms of an STI appear?

While most STIs take several days to weeks before symptoms appear, a few can cause symptoms within 48 hours of infection.

• Genital herpes: Symptoms typically appear 2-12 days after exposure. In rare cases, blisters or sores may appear as early as 48 hours.
• Gonorrhea: Symptoms usually appear 2-10 days after infection, but discharge or pain can develop within 48 hours in some cases.

Important: Not experiencing symptoms within 48 hours does not mean you are uninfected. Many STIs never cause noticeable symptoms, and the only way to be sure is to get tested.

Source: NHS, 2025; NSW Ministry of Health, 2025

Window Periods for STI Testing

The window period is the time between infection and when an infection can be detected by a test. Testing too early can lead to a false-negative result. The window period for each STI is as follows:

STI	Window Period
Chlamydia	7-14 days
Gonorrhea	7-14 days
Trichomoniasis	3-7 days
Syphilis	3 months
HIV	10-90 days
Hepatitis B	2-6 months
Herpes	3-6 weeks

Source: Queensland Positive People, n.d, MedPark Hospital, 2025; Melbourne Sexual Health Centre, n.d.; Centers for Disease Control and Prevention, 2025; Queensland Positive People, n.d.; Ada’s Medical Knowledge Team, 2024; Queensland Positive People, n.d.

STI Incubation Periods

The incubation period is the time between infection and the first appearance of symptoms. This differs from the window period, which relates to testing. The incubation periods per STI are summarized in the table below:

STI	Incubation Period
Chlamydia	1-3 weeks
Gonorrhea	Average of 5 days
Trichomoniasis	5-25 days
Syphilis	Average of 3 weeks
HIV	2-6 weeks
Hepatitis B	4 weeks to 6 months
Herpes	2-12 days

STIs without symptoms

Not all sexually transmitted infections cause visible or noticeable symptoms. In fact, a large percentage of people with STIs remain asymptomatic, meaning they do not develop any signs of infection even though they can still pass the infection to others. For example, studies show that up to 50-70% of chlamydia cases show no symptoms at all (CDC, 2025). This is why relying on symptoms alone is not a safe way to know if you have an STI. The only reliable method is to get tested according to the correct window period, even if you feel healthy.

Getting Tested

Although STIs are common and nothing to be ashamed of, discovering you may have one can feel stressful or overwhelming. If you have had unprotected sex or a partner has informed you they tested positive, it is a good idea to get tested.

There are two main types of home STI tests:

• Laboratory tests: more reliable, can test for a wider range of infections.
• Rapid tests: quick, but often less accurate and usually only test for one infection at a time

Source: Toskin, I. et al., 2017; Australian Government Department of Health and Aged Care, 2024

Prevention Tips

• Use condoms or dental dams during vaginal, anal, and oral sex to reduce the risk of transmission.
• Get vaccinated against HPV and hepatitis B, which are common viral STIs with effective vaccines.
• Limit the number of sexual partners or choose mutually monogamous relationships where both partners have tested negative.
• Test regularly if you are sexually active, especially if you have new or multiple partners.
• Communicate openly with partners about sexual health, testing history, and protection.
• Avoid sharing needles or sex toys unless they are properly cleaned or covered with a new condom.
• Seek medical care early if you notice any unusual symptoms, or if you think you may have been exposed.

Source: Australian Government Department of Health, Disability and Ageing, 2024

Summary

STIs can cause a range of symptoms that take varying amounts of time to appear. While it is possible to experience symptoms of an STI within 48 hours, this is not very common. If you test for an STI before having symptoms or before the window period is over, the test result may not be reliable. That is why it is important to check the incubation and window periods of various STIs if you are experiencing symptoms before getting tested, and to wait until the window period is over if you are not experiencing symptoms yet. 

References

Australian Government Department of Health and Aged Care. (2024, March 8). Testing for sexually transmissible infections. Retrieved August 29, 2025, from https://www.health.gov.au/sti/testing

Australian Government Department of Health, Disability and Ageing. (2024, March 5). Prevention of sexually transmissible infections. Retrieved August 29, 2025, from https://www.health.gov.au/sti/prevention

Centers for Disease Control and Prevention (CDC). (2025). Chlamydia – About. https://www.cdc.gov/chlamydia/about/?CDC_AAref_Val=https://www.cdc.gov/std/chlamydia/stdfact-chlamydia.htm

NHS. (2022, June 24). How soon do STI symptoms appear? https://www.nhs.uk/common-health-questions/sexual-health/how-soon-do-sti-symptoms-appear/

NHS 24. (2025, April 16). Genital herpes. NHS inform. Retrieved August 29, 2025, from https://www.nhsinform.scot/illnesses-and-conditions/sexual-and-reproductive/genital-herpes/

NSW Ministry of Health. (2025, May 29). Gonorrhoea fact sheet. Retrieved August 29, 2025, from  https://www.health.nsw.gov.au/Infectious/factsheets/Pages/gonorrhoea.aspx

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-c). Chlamydia trachomatis en lymfogranuloma venereum.LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/chlamydia-trachomatis-en-lymfogranuloma-venereum

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-d). Gonorroe. LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/gonorroe

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-e). Trichomonas vaginalis. LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/trichomonas-vaginalis

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-f). Syfilis. LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/syfilis

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-g). Hiv-infectie. LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/hivinfectie

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-h). Hepatitis B. LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/hepatitis-b

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (n.d.-i). Humaan papillomavirusinfectie (cervixkanker). LCI-richtlijnen. https://lci.rivm.nl/richtlijnen/humaanpapillomavirusinfectie-cervixkanker

Rijksinstituut voor Volksgezondheid en Milieu (RIVM). (2024). LCI‑richtlijn herpessimplexvirusinfecties. Geraadpleegd op 29 augustus 2025, van https://lci.rivm.nl/richtlijnen/herpessimplexvirusinfecties

Toskin, I., Blondeel, K., Peeling, R. W., Deal, C., & Kiarie, J. (2017). Advancing point of care diagnostics for the control and prevention of STIs: The way forward. Sexually Transmitted Infections, 93(S4), S81–S88. https://doi.org/10.1136/sextrans‑2016‑053073

Queensland Positive People. (n.d.). Chlamydia. Retrieved August 29, 2025, from https://www.qpp.org.au/information/looking-after-yourself/sexual-health/chlamydia/

MedPark Hospital. (2025, April 7). STD testing: Candidates, tests, when to start. Retrieved August 29, 2025, from https://www.medparkhospital.com/en-US/disease-and-treatment/std-testing

Melbourne Sexual Health Centre. (n.d.). Hepatitis C treatment guidelines. Retrieved August 29, 2025, from https://www.mshc.org.au/health-professionals/treatment-guidelines/hepatitis-c/

Centers for Disease Control and Prevention. (2025). Getting tested for HIV. Retrieved August 29, 2025, from https://www.cdc.gov/hiv/testing/index.html

Queensland Positive People. (n.d.). Syphilis. Retrieved August 29, 2025, from https://www.qpp.org.au/information/looking-after-yourself/sexual-health/syphilis/

Ada’s Medical Knowledge Team. (2024, September 12). Trichomoniasis test: How to test and read the results. Ada. Retrieved August 29, 2025, from https://ada.com/sexual-health/trichomoniasis-test/

Queensland Positive People. (n.d.). Gonorrhoea. Retrieved August 29, 2025, from https://www.qpp.org.au/information/looking-after-yourself/sexual-health/gonorrhoea/