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Sexual Health Guide

Written by Ada’s Medical Knowledge Team

Updated on

STD stands for sexually transmitted disease. This is an umbrella term for a number of conditions that are caused by viruses, bacteria, and parasites that get transferred from one person to another through oral, vaginal, and anal sex.

These conditions may be grouped under the same umbrella term, but they’re not all the same. Each STD has its own symptoms, needs its own specific treatment, and can cause different complications. What they all have in common is how you can prevent them. The best way to prevent an STD is to always use a condom the correct way, to talk openly with your partner about their sexual habits, and to get tested regularly.[1][2]

What is an STD?

STDs are a number of diseases that can be spread from one person to another through oral, vaginal and anal sex. They are caused by a virus, bacteria or parasite that is transmitted from one person to another.[1][2]

STDs are quite common and lots of people with an STD don’t know they have one. This is because STDs can be present for a long time without showing any symptoms.

Most STDs can be treated easily when treatment is started early. Untreated infections, on the other hand, may progress and put your health at serious risk. Infertility, cancer and a higher chance of other infections are possible complications of STDs. On top of that, undiagnosed and untreated STDs put sexual partners at risk too.[1][2]

The most effective way to avoid getting an STD is by practising safe sex using a condom and by talking to your partner about their sexual health. There’s also a vaccine available for hepatitis B and HPV.

If you think that you might be at risk of an STD, even if you’re not experiencing any symptoms, it’s important to get tested so that you know your status. The earlier an STD gets diagnosed, the better the outcome.[1][2]

What are typical STD symptoms?

STDs often present themselves as genital warts or ulcers and abdominal pain. Many people experience pain during sex or pain when urinating.

Symptoms of an STD in women are often vaginal discharge and unusual vaginal bleeding. STD symptoms in men may include urethral discharge or a burning sensation in the urethra. The urethra is the tube which allows urine to pass out of the body.

Besides these more general symptoms, most STDs present with specific symptoms. There are also many cases where infected people don’t show any signs of the infection.[2][3]

How are STDs transmitted?

STDs can be transmitted from an infected person to anyone, so it’s important to always practise safe sex. They can be transmitted in various ways, depending on the STD.

They’re mostly transmitted through semen or other bodily fluids during oral, vaginal or anal sex. Some STDs can be transferred through blood, such as HIV and hepatitis B, which can happen if needles are shared.

There are also some STDs such as herpes and syphilis, which can be transmitted through saliva. This means you can also get these STDs from kissing. Some blood-borne sexually transmitted diseases may also spread through kissing if both partners have an open wound around the mouth. However, this is very unlikely.

STDs can also be spread from a mother to her child during pregnancy, childbirth or while breastfeeding.[1][2]

Which diseases are classified as STDs?

There are many conditions that can be transmitted through sexual contact. The most common ones are:

Chlamydia is a common STD which doesn’t cause any symptoms in most cases. If there are symptoms present they can include discharge and pain while urinating. Chlamydia can cause many complications if left untreated.[4]

Gonorrhea, sometimes referred as “the clap”, is an STD that causes yellow discharge and pain while urinating.[5]

Hepatitis B is an inflammation of the liver caused by a virus that can be transmitted sexually. When left untreated, this infection can cause life-threatening complications.[6]

Genital herpes is an STD caused by a virus that causes painful blisters in the genital area. This virus stays dormant in the body and can cause outbreaks at moments when the immune system is down. The blisters may look like pimples as well and can spread beyond the genital area. This means that herpes can present itself as pimples on the buttocks, for example.[7]

HIV is a virus that attacks the immune system. This makes it harder for the body to fight off other bacteria and viruses. HIV can develop into AIDS over time.[8]

HPV is an STD as well. It’s the abbreviation for human papillomavirus and it’s one of the most common STDs. HPV goes away on its own in most cases, but in other cases it can also cause genital warts and cancer.[9]

Syphilis starts off as a painless sore or multiple sores that go away. After that, you might notice a rash on your skin, often accompanied by symptoms such as fever, fatigue and headaches. If untreated, syphilis can spread to vital organs such as the eyes, the brain and the heart. This can even happen decades after the infection first takes place.[10]

Trichomoniasis is a parasite infection that often doesn’t cause any symptoms. In other cases, it can cause itching of the genitals, discharge, and an unpleasant feeling when peeing or having sex.[11]

Scabies is a mite infection that causes a rash and intense itching. It spreads through skin-to-skin contact and so, while it’s not exclusively considered an STD, it can also be spread through sexual contact.[12]

Molluscum contagiosum is one of the less harmful STDs. You can get molluscum contagiosum through skin contact, after which it presents itself as small lumps on the skin. It often goes away on its own, without any complications.[13]

Donovanosis is caused by a bacteria. This condition presents itself as ulcers in the genital region that bleed easily.[14]

For more specific information about the treatment, prognosis and symptoms of each STD, you can visit dedicated articles by clicking on the links or consult with your doctor for more information.

Are sexually transmitted diseases curable?

Whether or not an STD is curable depends on the STD. There are a number of treatment options available to cure or slow down these diseases. Some STDs can be cured without going to the doctor. This is the case with molluscum contagiosum, for example, which goes away on its own. However, you should always ask your doctor for advice.

Other sexually transmitted diseases such as syphilis, chlamydia, trichomoniasis and gonorrhea require antibiotics. With early and correct treatment, most people can be cured without any complications.

There are also STDs such as hepatitis B, HPV, herpes and HIV that can’t be cured. They can only be managed with medication.

For all STDs the best cure is prevention. Using a condom and limiting your sexual contacts are the best ways to avoid these diseases. Vaccines also offer protection from HPV and hepatitis B.[2][6]

STD FAQs

Q: What does STD mean? STD stands for sexually transmitted disease. This refers to a group of conditions which are caused by a bacteria, virus or parasite that is transmitted during sexual activity.

Q: What STDs do exist? There are a lot of diseases which can be transmitted by sexual contact with an infected person. The most common ones are HPV, chlamydia, gonorrhea and syphilis.

Q: How do you get an STD? You can get an STD from sexual contact with an infected person. This happens mostly through oral, vaginal or anal sex. In some cases, they can be spread through skin-to-skin contact, sharing medical equipment or, in rarer cases, kissing.

Q: What does an STD look like? Different types of STDs can have different appearances. STDs often cause a rash, warts or bumps in the genital area.

Q: What STD can cause a rash? Syphilis in its second stage can cause a rash on your skin. Other causes of rash include genital herpes, scabies and genital warts.

Q: Where can I get STD tested? You can get tested for STDs with your doctor or at a center that specializes in sexual health.

Q: Can STDs go away? Some STDs such as molluscum contagiosum and HPV can go away on their own. Most STDs however do need treatment. It’s important to talk to your doctor about the necessary actions to take.

Q: What is the difference between STD vs STI? An STI, or sexually transmitted infection, is the infection with the virus, bacteria or parasite which can lead to an STD, which is a sexually transmitted disease.

Q: Can you get an STD from a toilet seat? Most viruses, bacteria and parasites that cause STDs can’t survive outside of the human body for too long. Although very unlikely, you can get trichomoniasis from a toilet seat, as the parasite survives for a short moment in damp environments. However, the parasite would have to be freshly deposited on the toilet seat and there would have to be direct contact between your genitals and the toilet seat.


  1. CDC (2021).STD Diseases & Related Conditions. Accessed May 8, 2022.

  2. WHO (2021). Sexually transmitted infections. Accessed May 8, 2022.

  3. Pregnancy, Birth and Baby (2021). STIs and pregnancy. Accessed May 9, 2022.

  4. NHS (2021). Chlamydia. Accessed May 9, 2022.

  5. NHS (2021). Gonorrhoea. Accessed May 9, 2022.

  6. Tu T. et al. (2020). Special Issue “Hepatitis B Virus Infection: From Diagnostics to Treatments”. Accessed May 20, 2022.

  7. CDC (2022). Genital Herpes-CDC Fact Sheet. Accessed May 9, 2022.

  8. NIH (2021). HIV and AIDS: The Basics. Accessed May 9, 2022.

  9. CDC (2022). Genital HPV Infection - Fact Sheet. Accessed May 9, 2022.

  10. CDC (2022). Syphilis - CDC Fact Sheet. Accessed May 9, 2022.

  11. CDC (2022). Trichomoniasis - CDC Fact Sheet. Accessed May 10, 2022.

  12. NHS (2020). Scabies. Accessed May 10, 2022.

  13. Better Health Channel (2020). Molluscum contagiosum. Accessed May 10, 2022.

  14. CDC (2021). Granuloma Inguinale(Donovanosis). Accessed May 10, 2022.

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