Very low urinary sodium excretion is a significant clinical manifestation of hyponatremia. The normal value of blood sodium is 142 mmol/L (135-145 mmol/L), and blood sodium below 135 mmol/L is considered hyponatremia. Urinary sodium volume: normal adult 70-90 mmol/24h, which is about 4,1-5,3 g of sodium chloride. if urinary Na+. Dietary principles for very low urinary sodium excretion: (a) moderate to eat some poultry, lean meat, fish. Such as smoked and cured pork, luncheon meat, scallops, beef. (b) The main sources of sodium in common foods are also; large red sausage, cereal bran, corn flakes, pickled cucumber, ham, green olives, luncheon meat, oats, potato flakes, sausage, seaweed, shrimp, soy sauce, tomato sauce, spinach, winter squash and eggplant, dried tofu, etc. (iii) For those with chronic sodium loss hyponatremia, attention should be paid to the amount of sodium supplementation should be twice the regular calculated amount, the rate of sodium supplementation should not be too fast, and the amount of magnesium and other mineral elements should be supplemented, such as; green leafy vegetables, coarse grains, nuts and other foods. (iv) If elderly patients have the following conditions during the stable period of chronic heart failure, there is no need to excessively restrict sodium intake, namely: long-term loss of appetite and malnutrition; long-term use of thiazide diuretics; combined hypoproteinemia and low blood sodium concentration monitoring, etc. In these cases, patients can have a daily salt intake of 4-5 grams, while eating more potassium-rich foods, such as bananas, strawberries, citrus, grapes, grapefruit, watermelon, spinach, yams, mao beans, amaranth, onions, etc. (E) avoid raw and cold, greasy food. (6) For early dilutional hyponatremia, strictly limit the amount of water given to the general diet or high sodium food. (7) For hyponatremia with heart disease and hypertension, avoid eating more salt. (viii) Pay attention to eat more salty food to replenish the salt lost in the body and achieve the balance required by the body.