Sagging skin may be caused by factors such as aging, weight changes, and poor nutrition. 1. Ageing: With ageing, the water and collagen in the skin will gradually be lost, which cannot support the fullness of the skin’s shape, and a state of skin laxity will occur. 2. Weight change: due to disease, weight loss and other factors lead to a short-term dramatic weight loss, subcutaneous adipose tissue volume shrinkage, will lead to skin laxity. 3. Nutritional deficiencies: Insufficient intake of nutrients or obstacles to absorption can lead to a lack of nutrients in the body, loss of fat and protein, and the lack of effective support for the skin can cause the symptoms of skin laxity. There are many factors that can cause skin laxity, and it is recommended that patients seek timely medical attention to identify the cause of the disease and then carry out the relevant treatment.