As the saying goes, “it’s hard to buy old people thin”, but in fact, the elderly suddenly lose weight in a short period of time, if the weight of an unexplained loss of more than 10 kg in a month, is often a signal of a serious disease, even if there is no other physical discomfort, but also to go to the hospital in time for a medical examination to identify the cause. The following conditions are common: 1, diabetes: the early manifestation of diabetes is “three more and one less”, that is, more food, more urine, more drink, accompanied by wasting (weight loss). This is due to the fact that the patient does not have enough insulin in the body (type 1 diabetes is absolute low insulin secretion, type 2 diabetes is relative insulin deficiency) and cannot use the glucose in the blood. Since the body always needs energy, it cannot use glucose and starts to consume fat, which results in wasting. 2.Cancer: such as colon cancer, pancreatic cancer, stomach cancer, etc. The early symptoms of cancer are not obvious. Since tumor needs nutrition to grow, it will compete with other organs of the body for nutrition, which leads to wasting, and wasting is one of its main symptoms. Therefore, for those who suddenly lose weight, especially for those who are over 50 years old, sudden loss of weight should raise alert. 3, cirrhosis: chronic liver disease patients are often too busy to face or work without timely medical treatment, if a couple of months to lose one or two dozen pounds, suddenly thin, to think about the possibility of cirrhosis. Cirrhosis, in severe cases, can appear ascites, often accompanied by weakness, jaundice and other uncomfortable symptoms. 4. Hyperthyroidism: If there is no decrease in food consumption, but weight loss all the time, accompanied by thick neck or panic, loss of eyes, etc., it is possible to suffer from hyperthyroidism. Hyperthyroidism in the elderly is not as easy to identify as in young people. About 1/3 of elderly patients do not have an enlarged thyroid gland, but mainly show wasting.