Some STDs have only mild symptoms or no symptoms at all. The only way to be sure you don’t have an STD is through testing. You may suspect that you have an STD based on your sexual history and symptoms, but laboratory testing will be needed to confirm the diagnosis. Common symptoms include painful urination, penile discharge, unusual vaginal discharge/odor, genital ulcers, painful intercourse, skin rash, swollen lymph nodes, sore throat, anal discharge/pain, etc. Unfortunately, some STDs, for instance Chlamydia, may not cause symptoms especially in women until it has caused significant damage to the reproductive organs.