Overview

Sexually transmitted diseases (STDs) — or sexually transmitted infections (STIs) — are generally acquired by sexual contact. The bacteria, viruses or parasites that cause sexually transmitted diseases may pass from person to person in blood, semen, or vaginal and other bodily fluids.

Sometimes these infections can be transmitted nonsexually, such as from mothers to their infants during pregnancy or childbirth, or through blood transfusions or shared needles.

STIs don’t always cause symptoms. It’s possible to contract sexually transmitted infections from people who seem perfectly healthy and may not even know they have an infection.

Symptoms

STDs or STIs can have a range of signs and symptoms, including no symptoms. That’s why they may go unnoticed until complications occur or a partner is diagnosed.

Signs and symptoms that might indicate an STI include:

• Sores or bumps on the genitals or in the oral or rectal area
• Painful or burning urination
• Discharge from the penis
• Unusual or odorous vaginal discharge
• Unusual vaginal bleeding
• Pain during sex
• Sore, swollen lymph nodes, particularly in the groin but sometimes more widespread
• Lower abdominal pain
• Fever
• Rash over the trunk, hands or feet

Signs and symptoms may appear a few days after exposure. However, it may take years before you have any noticeable problems, depending on the organism causing the STI.

When to see a doctor

See a doctor immediately if:

• You are sexually active and may have been exposed to an STI
• You have signs and symptoms of an STI