Common symptoms of low magnesium in the human body include convulsions, fatigue, muscle spasms, muscle cramps, weakness and numbness, according to MedlinePlus. Abnormal eye movements, or nystagmus, is also a possible symptom of low magnesium.
Low magnesium levels, or hypomagnesemia, can be caused by chronic diarrhea, alcoholism, malnutrition, malabsorption and hypoaldosteronism, as MedplinePlus explains. Excessive urination and high blood calcium levels can also cause low magnesium levels. Additionally, medications such as diuretics, proton pump inhibitors, amohotericin, cisplatin, cyclosporine and aminoglycoside antibiotics can also cause low magnesium levels. Low magnesium levels can be a life-threatening emergency, resulting in cardiac arrest, respiratory arrest and even death.