When elderly people experience gradual wasting, the first step is to identify the cause. Some elderly people are unable to eat or have insufficient intake due to diseases, such as sequelae of cerebrovascular disease, digestive tumors and other diseases, and these patients should actively deal with the primary disease while finding ways to increase nutritional intake. For example, patients who have difficulty swallowing can be fed with the help of a nasogastric tube or a nasogastric tube, or they can be fed with a gastrostomy. The food should include protein, sugar, vitamins, trace elements and water, and other essential nutrients, and should be injected in several times and in moderate amount, so as not to cause indigestion, reflux and aspiration due to excessive amount. Patients who cannot eat due to gastrointestinal tumor can take intravenous nutrition, including amino acid, fat, glucose, albumin and so on. There are also some patients caused by excessive consumption, such as patients with diabetes, hyperthyroidism, chronic obstructive pulmonary disease, and tumors, etc. The most important treatment for these patients is to deal with the primary disease, while ensuring adequate intake.