The common symptoms of hyperkalemia and hypokalemia, mainly seen in severe cases of high or low potassium, manifest as neurological and muscular symptoms as well as circulatory system symptoms, which are fairly similar in both conditions. If the blood potassium is particularly low, less than 2.0 mmol per liter, it can lead to reduced or absent reflexes. In severe cases, this may progress to paralysis of the respiratory muscles, causing respiratory pump failure. For hyperkalemia, particularly severe cases may also present with swallowing difficulties and respiratory distress. These central nervous system issues can lead to confusion and fainting. Another similar issue is the impact on the circulatory system; severe hypokalemia can cause ventricular tachycardia and even ventricular fibrillation, leading to death. In hyperkalemia, the impact on the cardiovascular system primarily causes malignant tachycardia and can also result in ventricular fibrillation. The main cause of sudden death in hyperkalemia is ventricular fibrillation and cardiac arrest, demonstrating that severe hyperkalemia and hypokalemia similarly cause significant arrhythmic conditions in the heart.