Reactive arthritis is joint pain and swelling triggered by an infection in another part of your body — most often your intestines, genitals or urinary tract.
Reactive arthritis usually targets your knees and the joints of your ankles and feet. Inflammation also can affect your eyes, skin and urethra.
Previously, reactive arthritis was sometimes called Reiter's syndrome, which was characterized by eye, urethra and joint inflammation.
Reactive arthritis isn't common. For most people, signs and symptoms come and go, eventually disappearing within 12 months.