Thousands of people have sexually transmitted diseases or STDs, and don't even know it.

This year about 19 million new cases have been reported involving sexually transmitted diseases or STDs. According to reports, almost half of the new infections involve ages 15 to 24 years old.

The most common STDs are herpes, gonorrhea and chlamydia. Health officials say some people with STDs never know they have one, which is steadily increasing the infection rate. The diseases are being passed person to person until someone gets sick.

In some std cases a person can have no symptoms for a period time. Chlamydia and gonorrhea are often a symptomatic.

Medication can control or cure some STDs but others like HIV and AIDS can not be cured and requires long term treatment.

Health officials say no matter what your age, if you're going to have sex, protect yourself.

Condoms are the most effective form of protection, except for abstinence. If condoms are used properly, STDs can be prevented.