Tetracycline is sometimes prescribed for the treatment of bacterial infections (those caused by the presence of bacteria, and not any virus, in the body). The following conditions can be treated: infections of skin, Lyme disease, Helicobacter pylori, respiratory tract infections, infection of genital and urinary systems, and acne. This drug can be also prescribed for the treatment of other conditions if recommended so by your health care provider. Make sure you tell your doctor if you get any serious side effects that may indicate your treatment is not going as planned, such as blurred vision, loss of appetite, dark-colored urine, jaundice, vomiting, fever or chills, skin rash, difficulty breathing, stomach pain, upset stomach, hives, itching, or severe headache. However, the serious side effect are not likely - in most cases you will just get a few mild side effects, for example, diarrhea, changes in skin color, sore mouth, redness of the skin, upset stomach, and itching of the rectum or vagina. The mild side effects mentioned do not need to be reported unless they change in intensity and get bothersome. Make sure you always tell your doctor if you notice any of your mild side effects changed in intensity.