High potassium or hyperkalemia is a medical emergency when detected at levels above 5ml/L. This is a level that you need to remember and be aware of. The principle reason this occurs is because of some kind of deficient kidney function or due to the action of some types of drugs. Potassium is one of the essential elements of the body that is necessary to maintain life. It is one of the main mechanisms of electricity generation in cells or the creation of action potentials. In muscles, it is the "off" switch for stopping contraction of muscles. This is why a condition in which you have deficient levels of potassium in your body will cause muscular spasms. Excessive amounts of potassium will then cause the muscle to remain in the off position. This is dangerous for muscles like the heart where one could develop arrhythmia.
Potassium works in muscles due the action of voltage-gated sodium channels. In the fibers of muscles, at a microscopic level, these channels open to allow sodium to be released and potassium to enter into them. This action is caused by a trigger from the brain that causes an energy reaction to open the sodium channel. Once the gate of the sodium channel is open, the potassium ions move in and shut down the action potential generated. Subsequent actions will cause calcium to source the contraction motion. Potassium levels, as with the levels of all electrolytes, is controlled within the kidneys. The kidneys do this using rows of cells that trap the bigger molecules like proteins and then subsequently by using mitochondrial reactions to pull out essential electrolytes like potassium and sodium. This is why kidney disease is the first area of suspicion in hyperkalemia. Note that hyperkalemia is induced in people who are facing death by lethal injection.
Treating this condition would require an intravenous administering of calcium, insulin, and salbutamol. High serum levels can also be dealt with using adrenaline and norepinephrine injections. It is important to prevent this condition by staying away from high potassium diets like tomatoes, potatoes, and oranges. It is important to prevent the condition by regularly exercising and drinking lots of water. All these may never really be completely adequate so the use of medication like thiazides and diuretics will be required. Having adequate salt in your diet is necessary to ensure that hyperkalemia is balanced out by adequate levels of sodium as well.
answered by M W