STIs often have no signs or symptoms (asymptomatic). If you have been at risk, by having unsafe sex, it is important to get tested to find [l1] out if you have attracted an STI. Even with no symptoms, you can pass the infection to your sex partners. Therefore, it is important to find out if you have an STI and it's also essential to inform your partner or partners so that they can be tested and treated.

Some STIs are easy to treat and cure; others require more-complicated treatment. If you suspect you have an STI or if you are diagnosed with an STI — make sure you get treated[l2] . If untreated, STIs can increase your risk of acquiring another STI such as HIV. This happens because an STI can stimulate an immune response in the genital area or cause sores, either of which might raise the risk of HIV transmission. Some untreated STIs can also lead to infertility.

Some of the following diseases, such as hepatitis, can be transmitted without sexual contact, by coming into contact with an infected person's blood. Others, such as gonorrhea, can only be transmitted through sexual contact.