Transmission electron micrograph (TEM) of a diplococcal pair of Type III, Gram-negative Neisseria gonorrhoeae bacteria. Gonorrhea is a sexually transmitted disease (STD). Gonorrhea is caused by Neisseria gonorrhoeae, a bacterium that can grow and multiply easily in the warm, moist areas of the reproductive tract, including the cervix (opening to the womb), uterus (womb), and fallopian tubes (egg canals) in women, and in the urethra (urine canal) in women and men. The bacterium can also grow in the mouth, throat, eyes, and anus.