Learn more about STIs, STI testing and treatment. STI cannot be treated online by our doctors.
Written by Medical Professional
Dr Adam Abbs
Claudia Jackson (RN)
Next Review: Oct 1, 2025
What are STIs?
STI is the abbreviation for a group of infections known as sexually transmitted infections. They may also be called sexually transmitted diseases (STDs).
STIs are infections caused by bacteria, viruses, or parasites that are passed from person to person, during unprotected sexual intercourse. STIs can also be passed from mother to baby during childbirth or breastfeeding or by sharing needles with IV drug users.
STIs are very common, and 317, 901 people in England were diagnosed with an STI in 2020.
Types of STIs
Types of STIs include:
- genital warts
- genital herpes
- pubic lice
- hepatitis B
- human papillomavirus (HPV)
- human immunodeficiency virus (HIV)
- mycoplasma genitalium (MG)
What are the symptoms of STI?
Symptoms of STIs vary according to which STI you have. Some STIs like chlamydia may have very mild, or no symptoms. It is possible to have an STI without knowing it and pass it on to your partner.
Some symptoms of an STI include:
- sores or bumps on the genitals (penis and vagina), mouth, or anus
- unusual, often strong-smelling discharge from the vagina
- discharge from the penis, or anus
- pain when urinating (peeing)
- rash on the trunk, hands, or feet
- pain during sex
- swollen, painful lymph nodes in the groin or other parts of the body
- unusual vaginal bleeding
- pain in your lower abdomen (belly)
- itching around the genitals or anus
- blisters and sores around your genitals or anus
- warts around your genitals, anus, or rarely your mouth or throat
If you have any of the above symptoms or think you have been exposed to an STI, it is important that you get an STI test. Do not have sex, including vaginal, oral, or anal sex, until you are sure that you do not have an STI.
How do you get an STI?
STIs are spread by bodily fluids (semen and vaginal fluids) during sexual activity or passed from mother to baby during childbirth or breastfeeding. They can be spread in the following ways:
- having unprotected (without a condom) vaginal, anal, or oral sex
- through genital touching without penetrative sex
- sharing sex toys without washing or covering them with a condom
- from mother to baby through childbirth and breastfeeding
Abstinence (not having sex) is the only guaranteed way to avoid getting an STI, but this is not realistic for most people.
Some things you can do to reduce your risk of getting an STI include:
- vaccination. Vaccines are available for some STIs like hepatitis B and human papillomavirus (HPV)
- limiting your sexual partners. Having multiple sexual partners increases your chances of getting an STI.
- being monogamous (having sex with one person who only has sex with you). Make sure you and your partner both get tested for STIs before beginning a sexual relationship.
- Using barrier methods of contraception like condoms, female condoms, and dental dams every time you have vaginal, anal, or oral sex.
How to get rid of STIs
The first step to getting treatment for an STI is to take an STI test to determine which type of STI you have. You can get an STI test at your GP, sexual health clinic, or order it online and do it yourself at home.
Home tests are available for many STIs including:
Many STIs are easily treated with antibiotics, but it’s important to start treatment as soon as possible to avoid passing the infection to others. Some STIs like chlamydia and syphilis can lead to serious health problems, so make sure you get tested and treated right away. If you test positive for an STI, you must inform your sexual partner and any former sexual partners so they can get tested and treated as well.
In the UK, it is recommended that all sexually active people under 25 years of age have a test for chlamydia once a year. You should also get tested for chlamydia whenever you have sex with a new partner.
How long after unprotected sex should I take an STI test?
STIs have what is known as a “window period”, which is the time it takes between getting the infection, and when it will show up on the test. This can be several weeks or months after the initial infection.
Chlamydia and gonorrhoea take around 14 days
HIV shows up on the test after 45 or 90 days, depending on the test
Syphilis has a window period of 12 weeks
If you are not sure when to take an STI test, take one straight away and make an appointment with your GP or local sexual health clinic for advice on when to take another test.
Treatment for STIs
The treatment for your STI will depend on which STI you are diagnosed with.
Bacterial or parasitic infections such as chlamydia, gonorrhoea, syphilis, and trichomoniasis are treated with a course of antibiotics
Viral infections like herpes, HIV, and hepatitis B cannot be cured, but are treated with antivirals to reduce the effects of the disease.
Can you diagnose and treat the STI online?
If you are worried about STIs and would like to talk about testing and treatment options, make an appointment with your local GP.
Our private online GP appointments are not suitable for STI diagnosis and treatment due to the complexity of the condition. If you have been tested positive for STIs, you might be referred to sexual clinic by your GP for further tests and treatment, therefore we recommend using the NHS services to get treated the soonest and most effectively.
NHS: Sexually transmitted infections (STIs) June 25th 2021 (Accessed August 24th 2022)
Office on Women`s Health February 22nd 2021 (Accessed August 24th 2022)
National Institute of Clinical Health Excellence: Reducing sexually transmitted infections June 15th 2022 (Accessed August 24th 2022)
Mayo Clinic: Sexually transmitted diseases (STDs) September 21st 2021 (Accessed August 24th 2022)
Public Health England: Sexually transmitted infections and screening for chlamydia in England, 2020 September 2021 (Accessed August 24th 2022)
NHS: Chlamydia September 1st 2021 (Accessed August 24th 2022)
NHS. Let’s talk about it: Testing & Treatment of STIs 2022 (Accessed August 24th 2022)
World Health Organisation: Sexually transmitted infections (STIs) 2022 (Accessed August 24th 2022)
Centers for Disease Control and Prevention: How you can prevent sexually transmitted diseases March 23rd 2022 (Accessed August 24th 2022)