Chlamydia is the most commonly reported sexually transmitted disease in the U.S. and yet only 38% of women aged 15 to 25 were screened in 2010, Reuters reported.

It can cause pain, infertility and problematic pregnancy, but few young women ever get tested for the disease.

U.S. Centers for Disease Control and Prevention estimates 1.3 million new cases in 2010. Still, since the STD often betrays no symptoms, the number could be twice as high, the organization said.

The disease is easily treated with antibiotics but can wreak havoc in women who don't know they're infected.

Without treatment, the Chlamydia infection can spread into the uterus or fallopian tubes and cause pelvic inflammatory disease.

The uterus and surrounding tissues can also become affected resulting in chronic pain, infertility and potentially fatal ectopic pregnancies.

The CDC has recommended that women be screened annually for chlamydia.

If an infection is found, the health organization recommends the patient return three months after being treated for a follow-up test.

SAFE SEX CAN BE GOOD FOR YOU

Testing rates were slightly better for older women and specific minority group - 42% of women aged 20 to 25 were tested. More than half of black women say they were been tested with 47% saying they had been screened in the prior year.

Men can contract chlamydia too - one in four show no symptoms while the others may experience symptoms similar to gonorrhea, including burning feeling while urinating, discharge and pain.