Sexually transmitted diseases (STDs), also called STIs (Sexually Transmitted Infections), are infections that are spread from one person to another during sexual activity, either vaginal, anal, and/or oral sex. 

STDs are common in sexually active people, and younger people are especially susceptible. The CDC estimates that those aged 15-24 years old account for half of new STIs in the US each year. 1 in 5 people in the US has an STD. If you fall in this age range, be sure to check out our tips for staying safe during your college years.

The best way to keep from getting an STD is to increase awareness and take steps toward prevention. Pandia Health cares about your well-being, which is why we created this resource so that you can learn the facts about STDs and make informed decisions about your sexual health.

A couple embracing by their waists

What Are Sexually Transmitted Diseases (STDs)?

STIs are caused by harmful bacteria, parasites, and viruses that wreak havoc on the reproductive systems and sometimes your whole body (syphilis, HIV). Formerly called venereal diseases, STDs are usually spread between sexual partners through skin-to-skin contact or bodily fluids. Mothers who test positive can also transmit STDs to their children during pregnancy, childbirth, and breastfeeding.

What Are the Most Common STDs?

The following 7 STDs are among the most common sexually transmitted infections. From most common to least common.

  • Human papillomavirus (HPV)
  • Genital Herpes simplex virus 2 (HSV or herpes) (12% of people 14-49 years old in the US have this)
  • Chlamydia (1.8 million new cases in 2019)
  • Trichomoniasis (2% of those with vaginas and 0.5% of those with penises 14-49 years old in the US have this)
  • Gonorrhea (1.6 million new cases in 2019)
  • Syphilis
  • HIV
  • Hepatitis B

How Do You Get an STD?

STDs are transmitted through physical sexual contact, and your risk of getting an STD increases with your number of sexual partners. You can minimize your risk by getting STD testing for you and your partner(s) before having sex. Condoms also help reduce your chances of getting an STD. However, know that just because someone tests negative for an STD, that doesn’t mean they don’t have any STDs. They may not have the ones you tested for. We don’t have commercially available tests for HPV for those with penises. We don’t usually test for HSV unless it’s a blood test.

What Are the Signs That I Have an STD?

Many times, there are no signs of an infection for many STIs. But when there are, the most common symptoms include discharge, odor, irritation, pain during sex, and/or painful urination. Learn more facts about the most common STDs below, including how they are spread, treatment options, and how to recognize the signs of infection.


Chlamydia is caused by a bacteria found in infected semen, pre-ejaculate, and vaginal fluids (sexual fluids). Chlamydia can infect the penis, vagina, cervix, anus, urethra, eyes, and throat. 

It’s one of the most common STDs, and most people who have it don’t show any symptoms. Sometimes people with chlamydia have painful urination. Women who are symptomatic may experience white or yellow vaginal discharge that smells bad. If you’re not sure whether your discharge is healthy, read our post about vaginal discharge and see a doctor.

Chlamydia is a bacterial STI that can be easily cured and treated with antibiotics. Without treatment, chlamydia can cause health problems later in life such as infertility.


Gonorrhea is another bacterial STI that can be easily treated and cured with a round of antibiotics. t’s transmitted through sexual activity and 50% of people with vaginas and 10% of those with penises with gonorrhea do NOT have symptoms. Gonorrhea is spread through sexual fluids and can infect the vagina, penis, rectum, throat, eyes.

Symptoms of gonorrhea in women can include painful or burning sensations when peeing, increased vaginal discharge, and vaginal bleeding between periods (spotting). Like many other STDs, if left untreated, gonorrhea can cause serious health issues. A pregnant person with gonorrhea can also give the infection to their baby during childbirth. Many states require antibiotic eyedrops/ointment applied at birth to prevent Gonorrhea and other infections of the baby’s eyes.

Hepatitis B

Hepatitis B is a liver infection caused by a virus (called the hepatitis B virus, or HBV). This virus can be transmitted through sexual fluids and blood. Hepatitis B can be a serious disease, making you more susceptible to developing liver conditions or liver cancer, and there is no cure. Using condoms and getting the Hepatitis B vaccine are both effective methods of prevention.

Herpes: Genital 

Herpes is a common virus that can cause sores on your face and body. Herpes is caused by two different viruses: herpes simplex 1 (HSV-1) and herpes simplex 2 (HSV-2)‒not to be confused with the human papillomavirus (HPV), which we will cover later.

Herpes is spread by skin-to-skin contact with infected areas such as oral sex, vaginal/anal sex, kissing. While herpes can be annoying and painful, it doesn’t usually lead to serious health problems, although once you have it‒you have it for life. Also there can be infections that go to the brain, the eyes of babies as they pass through the vagina, and mouth lesions can be so painful people can’t eat/drink.

Both genital and oral herpes can be caused by either of the two virus types coming in contact with the corresponding body part. 


Human Immunodeficiency Virus (HIV) is the virus that causes AIDS and can damage your immune system, making it easier for you to get sick and harder for you to recover. 

HIV spreads by having unprotected vaginal or anal sex, sharing needles, or getting HIV-infected blood, semen, or vaginal fluids into open cuts or sores.

While there is no cure for HIV, taking HIV medication helps treat the symptoms and can lower your chances of spreading the virus. Without treatment, HIV can lead to AIDS.


Human papillomavirus (HPV) is the most common STI. Most people with HPV have no symptoms. Many types of HPV are harmless and go away without treatment, but some types can lead to genital warts or cervical, throat, anal, and/or penile cancer.

While there is no treatment for HPV, you can try to prevent the virus from spreading or treat symptoms like genital warts. To prevent the virus from spreading, use a condom with every sexual act. The HPV vaccine can help protect you from getting 9 types of HPV. There are 160 types of HPV. Regular pap smears and annual health screenings can help you identify HPV early on before it has a chance to develop into something more serious.

Like almost all STIs, using condoms or dental dams can help lower your chances of getting HPV. 


Syphilis is a bacterial infection spread through vaginal, anal, and oral sex that can be cured with antibiotics, but if left untreated, it can lead to long-term health issues. 

Syphilis causes sores on your genitals that are usually painless but can easily spread to others through sexual contact. Using condoms or dental dams during sex can reduce transmission.

Without treatment, syphilis can lead to permanent medical conditions like brain damage, paralysis, and blindness. It’s important to get tested regularly for prompt treatment.

Like some other STIs, pregnant women can pass syphilis to a baby during pregnancy and childbirth (called congenital syphilis). STI testing is recommended 2-3 times during pregnancy to prevent STIs from spreading to the baby.


Trichomoniasis (“trich”) is caused by a parasite that’s in sexual fluids. Many with trich don’t have any symptoms and might not know they have it. When it does cause symptoms, the most common ones are irritation of the genitals, burning during urination, and abnormal discharge. Like many other STDs, condoms can help prevent you from getting trich, and medications can treat it.

Where Can I Get Tested for STDs?

STD testing is available at most health facilities. If you don’t feel like going to a doctor’s office, you’re in luck! Pandia is now offering a limited at-home testing kit (gonorrhea, chlamydia, and trichomonas only) for a quick, easy, and confidential sexual health check. Order yours today.

What Happens if I Don’t Get an STD Treated?

STDs can have long-term complications beyond the infection itself. STDs like herpes, gonorrhea, and syphilis can also increase the risk of HIV infection. Mother-to-child transmission of STIs can cause stillbirth, low-birth weight, and neonatal death. HPV can cause cervical, penile, and throat cancer. Gonorrhea and chlamydia can lead to reproductive damage and infertility in women. Hepatitis B can lead to liver disease or liver cancer. If you test positive for an STD, seek care and treatment immediately.

How to Avoid STDs

Other than abstinence and using condoms every time consistently and correctly, getting tested regularly and asking your partner to test is one effective way to decrease spreading or getting STDs. Here’s our blog on how STDs can also be prevented. Vaccines are also available to prevent some STDs like hepatitis B and HPV.

How Can Pandia Help?

Pandia is dedicated to providing accurate and reliable health information. Here, we gave you the facts about the most common STDs, but we have an entire library of information available to you to help you make informed, safe, and healthy decisions about your sexual health. Check out our Instagram and YouTube channel for more sexual well-being insights.

In addition to STD-related resources, Pandia also covers topics like birth control and offers FREE delivery for your birth control pills (also free if you have insurance) to your mailbox as well as free goodies with it! 

Get your at-home STD testing kit now. Don’t wait to get tested.

Disclaimer: This article, even if and to the extent that features the advice of physicians and medical practitioners, it is not, nor is it intended to be, a substitute for professional medical advice, diagnosis or treatment, and should never be relied upon for specific medical advice. Always seek the advice of your doctor/primary care provider for specific health needs.