STDs cause obvious symptoms. In men, common symptoms include:
pain or discomfort during sex or urination, sores, bumps, or rashes on or around the penis, testicles, anus, buttocks, thighs, or mouth. Unusual discharge or bleeding from the penis painful or swollen testicles.
Common STD symptoms in women include: pain or discomfort during sex or urination sores, bumps, or rashes on or around the vagina, anus, buttocks, thighs, or mouth unusual discharge or bleeding from the vagina itchiness in or around the vagina.