Interstitial edema is a group of renal diseases caused by a variety of different reasons to the renal interstitial inflammation as the main lesion, because interstitial nephritis almost always have renal tubular involvement, and therefore in recent years to “tubular a stromal disease” instead of interstitial nephritis this name. This disease can be classified into acute and chronic. Acute cases are mostly caused by infection, drug allergy, acute ischemia or poisoning, etc., which is characterized by rapid decrease of renal function; chronic cases are mostly caused by complicated chronic pyelonephritis with urinary tract obstruction, drugs, metabolic or immune diseases, etc., which is characterized by insidious onset and gradual onset of decrease of renal function. Patients with kidney disease may have eyelid edema, face edema, lower limb edema or even generalized edema. Regardless of the type of kidney disease, salt intake must be restricted as long as there is edema. When edema is obvious, it should be limited to less than 1 gram per day, and even require a salt-free diet in severe cases. When the urine protein reduces edema, the amount of salt can be increased appropriately, but should not exceed 5 grams per day. The purpose of a low-salt diet is to reduce the retention of water and sodium in the body, so that the edema subsides and the blood pressure falls. 1 to 2 grams of salt per day (about 1 gram when a small toothpaste cap is filled) Salt does not have to be put in the dish because it is also basically tasteless when it is put in the dish. In the morning, you can eat sweets; in the middle of the day, put l gram of salt in a small dish and eat it with vegetables; in the evening, use 5 ml of soy sauce (equivalent to 1 gram of salt) and eat it with vegetables. In this way, the total intake of 1 day remains unchanged, but can taste the salty flavor can stimulate the appetite. However, it should be noted that the low-salt diet can not eat pickles, kimchi, squash, salty bread, doughnuts, etc., and can not eat nori, rape, spinach, fennel, celery, broccoli, radish, etc.. Because these foods contain more than lOO mg of salt per 100 grams. Eating more of these foods is also equal to an increase in salt consumption.