Chlamydia is diagnosed during a gynecological examination that includes a medical history and pelvic examination. A physician may discuss sexual history, including number of sexual partners, past history of sexually transmitted diseases and use of contraception.

Because chlamydia often produces no symptoms, the only conclusive way to diagnose chlamydia is a laboratory test. Since the Centers for Disease Control and Prevention recommends that all sexually active women aged 25 years or younger receive a screening test, women may be given a test even if they have no symptoms. In addition, the Preventive Services Task Force (PSTF) recommends that all pregnant women aged 25 years or younger be screened for the disease.

There are two types of tests that detect chlamydia:

• Culture swab. For women, the physician may take a sample of vaginal discharge or mucous from the cervix with a swab. For men, the physician may insert a slim swab into the end of the penis to get a sample from the urethra. In some cases, a sample may be taken from the anus. The sample is then sent to a laboratory where it is studied for the presence of bacteria.
  
  
• Urine test. This may be performed on women and men. After collecting a sample of urine, it is sent to a laboratory where it is studied for the presence of the chlamydia bacteria.