This is an inflammation in which the kidneys are injured by infection or autoimmune disorders, or even by medications or toxins.
Symptoms include fever (due to inflammation), swelling of the body (due to injured kidneys causing water retention), and low back pain or abdominal pain. There is blood in the urine, which changes urine color to dark red or brown.
There are acute and chronic forms of nephritis. When you have above symptoms, please go to see your doctors for diagnosis and treatments.