Chlamydia
A common STI caused by the bacteria, Chlamydia trachomatis. Many people with chlamydia have no symptoms. When present, symptoms may include discharge or painful urination. Chlamydia is easily treated with antibiotics. If not diagnosed and treated, it can cause severe health problems.
Gonorrhea
A common STI caused by the bacteria, Neisseria gonorrhoeae. While many men exhibit symptoms of a gonorrheal infection, women usually do not. When gonorrhea symptoms do occur, they include pain or burning during urination and a yellowish discharge. Gonorrhea can be treated with antibiotics, but if left untreated, can cause severe complications.
Trichomonas
A common STI (also known as "trich") caused by the parasite, Trichomonas vaginalis. Most people infected with trichomonas cannot tell they are affected. Women may notice itching, burning, redness or soreness of the genitals, discomfort with urination or discharge. Men may feel itching or irritation inside the penis, burning after urination or ejaculation, or some discharge. Trichomonas can be treated with antibiotics.