After HPV (which we don’t routinely check for in teenagers) the most common STI in teens is chlamydia. It’s a bacterial infection that can be spread through oral, anal or vaginal sex. Infected individuals may not have symptoms at all, so the best thing to do if you are concerned that you have contracted chlamydia is to get tested.

Infected males may experience a funny discharge from their penis or pain with peeing. Infected females may experience an abnormal vaginal discharge or bleeding.