Physical examinations and other tests can be used to diagnose some STIs, including herpes and genital warts. Sores, bumps, and other signs of STIs can be found during a physical exam by your doctor. Alternatively, samples can be taken from any questionable areas for testing in a laboratory. In the event that you notice any changes on or around your genitals, it's important that you let your doctor know. Any changes on or around your anus or rectum should also be reported if you have anal sex. Urine or blood samples can be used to test for most STIs. It is possible for urine and blood tests to be less accurate than other forms of testing in some cases. Certain STIs may also take a month or more to be detected by blood tests after exposure. Still, they can be an effective option to check for gonorrhea, HIV, syphilis, and chlamydia. Checking for STIs is often done with the use of a vaginal, cervical, or urethral swab. In a pelvic exam, your doctor can take swabs from your vagina and cervical region using a cotton applicator. The urethral swabs are taken by inserting a cotton applicator into the urethra of someone who has a vagina or penis. To check for infectious organisms in your rectum, they may also take a rectal swab.