Megalocytic interstitial nephritis is a rare chronic kidney disease that is characterized by inflammation of the kidney. The inflammation is mainly found in an area of the kidney called the renal cortex, which is in the outer portion of the kidney. The exact cause of megalocytic interstitial nephritis is not clear; however, it is associated with an impaired function of histiocytes (immune cell that eats foreign substances to protect the body from infection), particularly in patients that have a lowered immune system. Alcohol abuse may also be a risk factor. Generalized symptoms of kidney inflammation (interstitial nephritis) may include: blood in the urine, fever, increased or decreased urine output, mental status changes, rash, and swelling of the body. Treatment is dependent on the underlying cause (if identified) and the stage of the disease.

Symptoms of generalized megalocytic interstitial nephritis may include blood in the urine, fever, increased or decreased urine output, mental status changes (drowsiness, confusion, coma), nausea, vomiting, rash, swelling of the body, and weight gain (from retaining fluid).