Step 1: Name a sexually transmitted disease.
One sexually transmitted disease is Gonorrhea.
Step 2: Describe its condition.
Gonorrhea is caused by the bacterium Neisseria gonorrhoeae. It primarily infects the genital tract but can also affect the rectum, throat, and eyes. Symptoms include painful urination, abnormal discharge, and in women, pelvic pain. If untreated, gonorrhea can lead to infertility, pelvic inflammatory disease (PID), and increase the risk of HIV.
Final Answer:
\[
\boxed{\text{Gonorrhea}}
\]