How Do Doctors Test for STDs?

About STD Testing

Sexually-transmitted diseases, or STDs, are diseases that are spread and contracted through sexual contact. Many can cause serious complications or health problems, so it's important to get tested for STDs if you suspect that you may have been infected by a partner. What type of STD testing will be performed will depend on the type of sexually transmitted disease you suspect that you have, but there are a few basic methods used to test for the many different types of STDs.

Physical Exam

Sometimes, all a doctor needs to do to diagnose an STD is to perform a physical exam and look at the genital area. Genital herpes can cause blisters that appear on the genitals and can be diagnosed just by looking at them (as long as the blisters appear, which they don't always). A rash, lesions or unusual discharge may also signify an STD, says Planned Parenthood.

Urine Testing and a Sample

A urine sample can be collected by urinating into a cup; then the doctor can diagnose STDs such as gonorrhea or chlamydia, says the Mayo Clinic. Those STDs can also be diagnosed by collecting and studying a sample of cells from just inside the penis or the cervix using a swab.

Blood Testing

A simple blood test---with a sample collected via a needle in the arm---can test for many types of STDs. HIV/AIDS, hepatitis A, hepatitis B and syphilis will need a blood test for diagnosis, says the Mayo Clinic.