A sexually transmitted disease (STD) is a disease which spreads by having sex. STDs can spread through oral sex or anal sex, or when two people’s genitals touch. Today, STDs are usually called sexually transmitted infections (STIs). In the past, they were called venereal diseases (VD).

STDs can be caused by viruses, bacteria, or parasites. Examples of the most common STDs are listed on this page.

The term sexually transmitted disease (STD) is used to refer to a condition passed from one person to another through sexual contact. You can contract an STD by having unprotected vaginal, anal, or oral sex with someone who has the STD.

An STD may also be called a sexually transmitted infection (STI) or venereal disease (VD).

That doesn’t mean sex is the only way STDs are transmitted. Depending on the specific STD, infections may also be transmitted through sharing needles and breastfeeding.

Symptoms of STDs in men

It’s possible to contract an STD without developing symptoms. But some STDs cause obvious symptoms. In men, common symptoms include:

pain or discomfort during sex or urination

sores, bumps, or rashes on or around the penis, testicles, anus, buttocks, thighs, or mouth

unusual discharge or bleeding from the penis

painful or swollen testicles



Symptoms of STDs in women

In many cases, STDs don’t cause noticeable symptoms. When they do, common STD symptoms in women include:

pain or discomfort during sex or urination

sores, bumps, or rashes on or around the vagina, anus, buttocks, thighs, or mouth

unusual discharge or bleeding from the vagina

itchiness in or around the vagina

The specific symptoms can vary from one STD to another

HIV or AIDS

HIV can damage the immune system and raise the risk of contracting other viruses or bacteria and certain cancers.