Ammonia blood mainly comes from dietary protein, which is unabsorbed in intestine. The protein is broken down by bacteria and passes into bloodstream where it is taken to the liver and converted to urea. Urea is excreted from the body in urine by kidneys. Having high blood levels of ammonia may affect brain function. It is crucial that people maintain normal ammonia levels in blood to avert affects on the brain function.
High ammonia levels in blood may occur due to chronic liver disease, gastrointestinal bleeding, and acute liver failure. Higher amounts of ammonia in blood than normal may induce neurological changes, which cause issues such as sleeplessness, confusion, and disorientation.
How ammonia is converted to urea
In your gut, there is good bacterial flora that helps in digestion of protein. The unabsorbed protein is acted upon by the good bacteria and broken down to form a compound known as ammonia. Ammonia travels thought portal vein to liver where it is converted to glutamine and then urea.
When glutamine it is converted to urea, it diffuses in blood cells in liver and moved to the kidneys where is excreted from body. When the liver is ill, it may fail to adequately convert ammonia to glutamine. In such a situation, it results in accumulation of ammonia in blood. The ammonia may reach the brain and result in changes.
What ammonia levels are considered normal
While the ammonia levels may vary from one lab to another, individuals who are tested for this substance in body should check the ranges with their labs. In general, adults will have normal ammonia levels ranging from 9.5 to 45 micrograms in every deciliter. The measures are given in mcg/Dl.
In children, the normal range of ammonia is considered to be somewhere between 40 and 80 micrograms per deciliter or mcg/dL. In infants or newborns, normal levels of ammonia are between 90 and 150 mcg/dL. These ranges are however used as guidelines or reference range because they can different from one lab to another.
Causes of high ammonia levels in blood
Ammonia is converted in the liver to glutamine before it is broken down to urea to be released by the kidneys in urine. Failure in liver function may cause high concentration of ammonia in blood. There are various conditions, which may impair the functioning of liver such as decompensated cirrhosis.
Long standing liver disease may cause advanced liver scarring or cirrhosis. When liver failure develops, it impairs the ability of the organ to detoxify the body meaning toxic chemicals like ammonia continue to accumulate. High blood ammonia will cause problems like tremors, slurred speech, sleep disturbances, confusion, abnormal eye movements, and drowsiness.
A rare condition known as Reye’s syndrome is associated with liver and brain function. Patients will this condition will have characteristically elevated levels of ammonia in blood. A patient with this condition will experience swelling of brain and when this is coupled with ammonia toxicity, it results in agitation, irritability, drowsiness, and confusion. The patient may have coma and seizures in severe cases of the condition.
Another cause of high levels of ammonia is gastrointestinal bleeding. Red blood cells tend to contain high amount of protein. Whenever there is bleeding in the upper gut, it increases the load of protein in intestines thereby causing increased production of ammonia.
Other conditions that may lead to high level of ammonia are such as leukemia, congestive heart failure, high body temperatures, metabolic alkalosis, and genetic diseases affecting the urea cycle.
How ammonia can be toxic to the brain and body
Ammonia is regarded as toxic to the brain. New studies are indicating that ammonia in brain may overpower it. When there is excess ammonia reaching brain, it causes the glial cells to be impaired in their ability to remove potassium.
Scientists have been working to find out how ammonia toxicity affects brain. The new study led by Professor Erlend Nagelhus in conjunction with American scientists has uncovered crucial information, which tries to shed light on how the brain is affected by ammonia toxicity.
While in healthy people, ammonia is converted to urea, in people with liver problems, they are unable to do away with ammonia as needed. This in turn results in excessive build up of the substance in blood. Ammonia toxicity may result thereof, leading to seizures and coma. When excess ammonia gets into the brain’s central nervous system, it will challenge the defenses of brain in a severe manner.
A molecular chain reaction occurs when exposure to excess ammonia occurs in brain. Ammonia causes short-circuits within the system that transports potassium to glial cells of brain. What this means is that, potassium will build up around nerve cells. This results to excess absorption of potassium as well as chloride by the cells.
Early diagnosis as well as treatment of high amount of ammonia in blood can help reduce the risks, which may bring life threatening complications in patients.