Hypouricemia is not a medical condition itself (i.e., it is benign), but it is a useful medical sign. Usually hypouricemia is due to drugs and toxic agents, sometimes it is due to diet or genetics, and rarely it is due to an underlying medical condition. When one of these causal medical conditions is present, hypouricemia is a common sign.

Hypouricemia is a level of uric acid in blood serum that is below normal. In humans, the normal range of this blood component has a lower threshold set variously in the range of 2 mg/dL to 4 mg/dL, while the upper threshold is 530 micromol/L (6 mg/dL) for women and 619 micromol/L (7 mg/dL) for men. Hypouricemia usually is benign and sometimes is a sign of a medical condition.

Interstitial nephritis (or tubulo-interstitial nephritis) is a form of nephritis affecting the interstitium of the kidneys surrounding the tubules, i.e., is inflammation of the spaces between renal tubules. This disease can be either acute, meaning it occurs suddenly, or chronic, meaning it is ongoing and eventually ends in kidney failure.

At times, there are no symptoms of this disease, but when they do occur they are widely varied and can occur rapidly or gradually. When caused by an allergic reaction, the symptoms of acute tubulointerstitial nephritis are fever (27% of patients), rash (15% of patients), and enlarged kidneys. Some people experience dysuria, and lower back pain. In chronic tubulointerstitial nephritis the patient can experience symptoms such as nausea, vomiting, fatigue, and weight loss. Other conditions that may develop include hyperkalemia, metabolic acidosis, and kidney failure.