Eosinophils are made in bone marrow and circulated to different tissues. The abnormal increase of eosinophils in the body for a longer period is called eosinophilia and it may cause chronic inflammation. The abnormal presence of eosinophils in the urine is known as Eosinophilia. Due to allergic reaction the presence of eosinophils in the urine is seen as acute interstitial nephritis. Eosinophils in urine causes diseases like cystitis, prostatitis, pyelonephritis, and glomerulonephritis, Acute Kidney Injury (AKI).Eosinophils become active due to certain allergic diseases, infections or inflammation. In case of Acute Interstitial Nephritis (AIN), patients may suffer from elevation in creatinine or blood urea nitrogen (BUN).