Chlamydia is an STI caused by a bacteria and spread through sexual fluids, including vaginal fluid and semen. You can get it from vaginal sex, anal sex, oral sex, or sharing sex toys with someone who has chlamydia. It often has no symptoms but can be cured with antibiotics.
Syphilis is an STI that starts as a painless sore. It can cause many different symptoms including rash, swollen lymph nodes and even brain damage and blindness.
Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI). There are many different types of HPV, some more serious than others. The good thing is that there is a vaccine to prevent many types of HPV.