Occasional nocturnal leg cramps are often a benign symptom and not a disease. It may also be associated with hyponatraemia and peripheral neuropathy. Acute renal failure, hyperaldosteronism, right heart failure, constrictive pericarditis, inferior vena cava obstruction, portal vein obstruction, nephrotic syndrome, hypoproteinaemia, cirrhosis, malignancy, advanced cirrhosis and malnutrition can cause hyponatraemia and nocturnal leg cramps, but they are often accompanied by other symptoms and do not have nocturnal leg cramps as the It is not the first and main symptom.