Medically reviewed by Ada Stewart, M.D.
Sexually transmitted infections (STIs) are the last thing you want to think about when you’re on duty. But sexually active military personnel are at high risk for contracting an STI. And servicemembers with female biology are diagnosed with STIs at higher rates than men.
If you are sexually active, the only way to protect yourself from getting an STI is to use latex or polyurethane condoms or dental dams every time you have sex. Many infections have similar signs or none at all, so we’ve created a quick guide to help you understand more about common STIs.
| Chlamydia | |
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What It Is |
Symptoms |
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A common STI caused by bacteria. Can cause infertility in those with female biology if it’s not treated. |
Often has no symptoms. When symptoms occur, they may come weeks after sex with an infected person. Symptoms may include:
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Causes |
Treatment |
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Unprotected vaginal, anal or oral sex with an infected person; ejaculation does not have to occur. Passing the infection to a newborn during childbirth. |
A 1- or 7-day course of antibiotics, prescribed by a medical provider. Infected individuals should avoid having sex for seven days following a single dose or until completion of the 7-day antibiotic course to prevent spreading. Patients should be retested 3 months after treatment to make sure the infection is gone. Left untreated for too long, chlamydia can cause pelvic inflammatory disease, increasing the risk of infertility for people with female biology. |
Chlamydia
A common STI caused by bacteria. Can cause infertility in those with female biology if it’s not treated.
Often has no symptoms.
When symptoms occur, they may come weeks after sex with an infected person.
Symptoms may include:
- Vaginal discharge
- Burning or pain when peeing
- Rectal pain, discharge and bleeding
Unprotected vaginal, anal or oral sex with an infected person; ejaculation does not have to occur.
Passing the infection to a newborn during childbirth.
A 1- or 7-day course of antibiotics, prescribed by a medical provider.
Infected individuals should avoid having sex for seven days following a single dose or until completion of the 7-day antibiotic course to prevent spreading.
Patients should be retested 3 months after treatment to make sure the infection is gone.
Left untreated for too long, chlamydia can cause pelvic inflammatory disease, increasing the risk of infertility for people with female biology.
| Gonorrhea (“the clap”) | ||||||||||||||||||||||||
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What It Is |
Symptoms |
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A common STI caused by bacteria. It can infect the pharynx (throat), cervix, uterus and fallopian tubes. |
Often has no symptoms. When symptoms occur, they may include:
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Causes |
Treatment |
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Unprotected vaginal, anal or oral sex with an infected partner; ejaculation does not have to occur. Passing the infection to a newborn during childbirth. |
A single dose of an antibiotic. The medication should kill the infection but will not repair any damage done by the bacteria. Infected individuals should avoid having sex during treatment and retest four to seven days after treatment if they still have symptoms. Everyone should follow up at 3 months. Left untreated for too long, gonorrhea can cause pelvic inflammatory disease, increasing the risk of infertility for people with female biology. Completely untreated, gonorrhea can move into the bloodstream, where it can cause a potentially life-threatening infection. |
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Gonorrhea (“the clap”)
A common STI caused by bacteria. It can infect the pharynx (throat), cervix, uterus and fallopian tubes.
Often has no symptoms. When symptoms occur, they may include:
- Pain when peeing and increased vaginal discharge
- Rectal discharge, itching, soreness and painful bowel movements
Unprotected vaginal, anal or oral sex with an infected partner; ejaculation does not have to occur.
Passing the infection to a newborn during childbirth.
A single dose of an antibiotic. The medication should kill the infection but will not repair any damage done by the bacteria. Infected individuals should avoid having sex during treatment and retest four to seven days after treatment if they still have symptoms. Everyone should follow up at 3 months.
Left untreated for too long, gonorrhea can cause pelvic inflammatory disease, increasing the risk of infertility for people with female biology.
Completely untreated, gonorrhea can move into the bloodstream, where it can cause a potentially life-threatening infection.
| Hepatitis A, B and C | ||||||||||||||||||||||||
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What It Is |
Symptoms |
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Inflammation of the liver. |
Often has no symptoms. When symptoms occur, they may include:
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Causes |
Treatment |
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Hepatitis A: Unprotected sexual contact with an infected person. Sharing needles or other drug injection equipment. Getting contaminated food, drinks or feces from an infected person in the mouth. Hepatitis B: Unprotected sexual activity with an infected person. Sharing needles or other drug injection equipment. Hepatitis C: Unprotected sexual activity with an infected person. Sharing needles or other drug injection equipment. |
Acute or suddenly appearing hepatitis may go away on its own or with rest and hydration. Chronic or long-term hepatitis may need medication, surgery or a transplant, depending on the type and severity. A vaccine is available to prevent infection with hepatitis A and B. |
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Hepatitis A, B and C
Inflammation of the liver.
Often has no symptoms. When symptoms occur, they may include:
- Fever
- Fatigue
- Loss of appetite
- Nausea
- Vomiting
- Abdominal pain
- Dark urine
- Light-colored stools
Hepatitis A:
Unprotected sexual contact with an infected person.
Sharing needles or other drug injection equipment.
Getting contaminated food, drinks or feces from an infected person in the mouth.
Hepatitis B:
Unprotected sexual activity with an infected person.
Sharing needles or other drug injection equipment.
Hepatitis C:
Unprotected sexual activity with an infected person.
Sharing needles or other drug injection equipment.
Acute or suddenly appearing hepatitis may go away on its own or with rest and hydration.
Chronic or long-term hepatitis may need medication, surgery or a transplant, depending on the type and severity.
A vaccine is available to prevent infection with hepatitis A and B.
| Herpes | |
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What It Is |
Symptoms |
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A viral infection. There are two types of herpes simplex virus: type 1 (HSV-1) and type 2 (HSV-2). Oral herpes, often described as cold sores, is caused by HSV-1. Genital herpes can be caused by HSV-1 and HSV-2. |
Symptoms can range from none to mild to severe. When people have symptoms, it’s called an “outbreak.” Oral herpes may appear as a pimple, sore, or blisters around the mouth or nose. Genital herpes may appear as blisters or painful sores around the genitals, rectum or mouth. Flu-like symptoms might occur during an outbreak. |
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Causes |
Treatment |
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Direct contact with a herpes sore, or from the saliva or the skin in and around the mouth or genitals of someone with an active infection through unprotected sex or kissing. Lesions or sores do not have to be present to spread the virus. |
There’s no cure, but antiviral medicine can help prevent outbreaks and spreading, help sores heal, and lessen the severity of symptoms during an outbreak. |
Herpes
A viral infection. There are two types of herpes simplex virus: type 1 (HSV-1) and type 2 (HSV-2).
Oral herpes, often described as cold sores, is caused by HSV-1. Genital herpes can be caused by HSV-1 and HSV-2.
Symptoms can range from none to mild to severe. When people have symptoms, it’s called an “outbreak.”
Oral herpes may appear as a pimple, sore, or blisters around the mouth or nose.
Genital herpes may appear as blisters or painful sores around the genitals, rectum or mouth.
Flu-like symptoms might occur during an outbreak.
Direct contact with a herpes sore, or from the saliva or the skin in and around the mouth or genitals of someone with an active infection through unprotected sex or kissing. Lesions or sores do not have to be present to spread the virus.
There’s no cure, but antiviral medicine can help prevent outbreaks and spreading, help sores heal, and lessen the severity of symptoms during an outbreak.
| Human Immunodeficiency Virus (HIV) | |||||||||||||||||||||||||||||||||||||||||||||||||
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What It Is |
Symptoms |
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A virus that attacks the body’s immune system. |
Often has no symptoms, but flu-like symptoms might occur within a month of infection. People with female biology may experience:
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Causes |
Treatment |
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Unprotected anal or vaginal sex. Sharing needles or other drug injection equipment. Passing the infection to a newborn during childbirth. |
There is no cure for HIV, but antiretroviral therapy (ART) can lower the amount of the virus in the body and lessen the chance of spreading it. If left untreated, HIV can lead to acquired immunodeficiency syndrome (AIDS). |
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Human Immunodeficiency Virus (HIV)
A virus that attacks the body’s immune system.
Often has no symptoms, but flu-like symptoms might occur within a month of infection.
People with female biology may experience:
- Changes in menstrual bleeding
- Pelvic pain
- Pain during sex
- Vaginal yeast infections
Unprotected anal or vaginal sex.
Sharing needles or other drug injection equipment.
Passing the infection to a newborn during childbirth.
There is no cure for HIV, but antiretroviral therapy (ART) can lower the amount of the virus in the body and lessen the chance of spreading it.
If left untreated, HIV can lead to acquired immunodeficiency syndrome (AIDS).
| Human Papillomavirus (HPV) | |||||||||||||||||||||||||||||||||||||||||||||||||
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What It Is |
Symptoms |
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A common group of viruses. There are more than 100 different types of HPV that cause a variety of skin warts as well as genital warts. Certain types are responsible for causing some types of cancer. |
Most people don’t have any symptoms of HPV. Symptoms of certain types of HPV can include warts on the vulva, near the anus or cervix, or in the vagina. |
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Causes |
Treatment |
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Unprotected vaginal, anal or oral sex with someone with the virus. Close skin-to-skin touching in the genital region. |
There’s no cure for the HPV virus in the body, but the warts and lesions can be treated topically. A vaccine is available to prevent infection and related cancers. |
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Human Papillomavirus (HPV)
A common group of viruses. There are more than 100 different types of HPV that cause a variety of skin warts as well as genital warts. Certain types are responsible for causing some types of cancer.
Most people don’t have any symptoms of HPV.
Symptoms of certain types of HPV can include warts on the vulva, near the anus or cervix, or in the vagina.
Unprotected vaginal, anal or oral sex with someone with the virus.
Close skin-to-skin touching in the genital region.
| Pubic Lice/Crabs | |
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What It Is |
Symptoms |
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Parasitic insects, usually found in the genital area, but can be found on other types of coarse body hair. Exist in 3 stages: eggs (nits); nymphs; and adults, which feed on blood. |
Symptoms may include:
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Causes |
Treatment |
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Sexual contact with a person who has the parasite. (Condoms cannot prevent pubic lice.) Sharing bedding, towels or clothes with a person who has the parasite. |
Topical gels, shampoos, liquids and foam medications are available over the counter. If the pubic lice don’t go away with over-the-counter treatment or if the pubic lice are in facial hair, individuals may need to see a medical provider for prescription medication. |
Pubic Lice/Crabs
Parasitic insects, usually found in the genital area, but can be found on other types of coarse body hair.
Exist in 3 stages: eggs (nits); nymphs; and adults, which feed on blood.
Symptoms may include:
- Itching in the genital area
- Dark bluish or pale spots on skin
- Small tan or white bugs, or yellow or white nits in pubic hair
Sexual contact with a person who has the parasite. (Condoms cannot prevent pubic lice.)
Sharing bedding, towels or clothes with a person who has the parasite.
Topical gels, shampoos, liquids and foam medications are available over the counter. If the pubic lice don’t go away with over-the-counter treatment or if the pubic lice are in facial hair, individuals may need to see a medical provider for prescription medication.
| Scabies | |
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What It Is |
Symptoms |
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A skin rash caused by a mite. The mite burrows into the upper layer of skin, where it lives and lays eggs. |
Intense itching and a pimple-like rash. Symptoms might not appear for 4-6 weeks. |
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Causes |
Treatment |
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Direct skin-on-skin contact. Sharing bedding, towels or clothing with an infected person. Sexual contact with someone with scabies. |
A prescription lotion or cream called scabicide must be applied to the entire body. People who have had close contact with the affected person also should be seen by a medical provider. |
Scabies
A skin rash caused by a mite. The mite burrows into the upper layer of skin, where it lives and lays eggs.
Intense itching and a pimple-like rash. Symptoms might not appear for 4-6 weeks.
Direct skin-on-skin contact.
Sharing bedding, towels or clothing with an infected person.
Sexual contact with someone with scabies.
A prescription lotion or cream called scabicide must be applied to the entire body. People who have had close contact with the affected person also should be seen by a medical provider.
| Syphilis | |
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What It Is |
Symptoms |
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A serious illness caused by bacteria. |
Symptoms occur in stages and typically start with painless, firm, round sores where syphilis entered the body. Second-stage symptoms include:
A rare third stage, or hidden stage, can come 10-30 years after infection, which can harm the organs and lead to death. The hidden stage can come at any time after infection and presents no signs or symptoms. |
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Causes |
Treatment |
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Direct contact with a syphilis sore during unprotected vaginal, anal or oral sex. Passing the infection to a newborn during childbirth. |
Antibiotic injection(s). Left untreated, syphilis can damage the organs and the cardiovascular and nervous systems, and even lead to death. |
Syphilis
A serious illness caused by bacteria.
Symptoms occur in stages and typically start with painless, firm, round sores where syphilis entered the body.
Second-stage symptoms include:
- Rough, red rashes on the palms and the bottoms of the feet
- Large gray or white lesions in the mouth or groin area
A rare third stage, or hidden stage, can come 10-30 years after infection, which can harm the organs and lead to death.
The hidden stage can come at any time after infection and presents no signs or symptoms.
Direct contact with a syphilis sore during unprotected vaginal, anal or oral sex.
Passing the infection to a newborn during childbirth.
Antibiotic injection(s).
Left untreated, syphilis can damage the organs and the cardiovascular and nervous systems, and even lead to death.
| Trichomoniasis (Trich) | |||||||||||||||||||||||||||||||||||||||||||||||||
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What It Is |
Symptoms |
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A common infection caused by a parasite. Trich occurs more often in women than men. |
Most people do not have symptoms. But if they do, symptoms may include:
Clear, white, yellowish, or greenish vaginal discharge with a fishy smell |
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Causes |
Treatment |
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Unprotected vaginal, oral or anal sex with an infected person. |
Oral antibiotics for 7 days. |
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Trichomoniasis (Trich)
A common infection caused by a parasite. Trich occurs more often in women than men.
Most people do not have symptoms. But if they do, symptoms may include:
- Discomfort during sex
- Itching, burning, redness or soreness in the vulva
- Discomfort or pain when peeing
Clear, white, yellowish, or greenish vaginal discharge with a fishy smell
Unprotected vaginal, oral or anal sex with an infected person.
Oral antibiotics for 7 days.
