What is an elevated blood ammonia level? Ammonia is a nitrogen waste compound that is normally excreted in the urine. An elevated blood ammonia level is an excessive accumulation of ammonia in the blood. An elevated blood ammonia level occurs when the kidneys or liver are not working properly, allowing waste to remain in the bloodstream. Ammonia, like many other waste products in the body, can be poisonous to your cells, and an elevated blood ammonia level can affect your entire body. Elevated blood ammonia can affect a person at any age and happens for a variety of reasons. It is fairly common in infants, in whom the disease can be related to a genetic condition. In children, it may be related to Reye’s syndrome, while in adults, an elevated blood ammonia level may indicate kidney or liver damage or an underlying metabolic disease. In some cases, an elevated blood ammonia level will resolve on its own without treatment. In addition to an increased level of ammonia in the blood, other symptoms of elevated blood ammonia include muscle weakness, fatigue, or other symptoms of liver and kidney damage and failure. If left untreated, elevated blood ammonia can affect brain tissue, leading to symptoms such as confusion and delirium (rapid change in cognitive function). An elevated blood ammonia level may also be related to drug or alcohol abuse. Treatment for an elevated blood ammonia level varies depending on the cause. If related to drug or alcohol abuse, treating the underlying cause may resolve the elevated blood ammonia level. Treatment includes medication, dialysis, or organ (kidney or liver) transplant. Seek immediate medical care (call 911) if you, or someone you are with, have serious symptoms, such as sudden confusion or loss of consciousness for even a brief moment, and sudden changes in mood, personality or behavior. Seek prompt medical care if you are being treated for elevated blood ammonia level and your symptoms recur or are persistent.