Lactose intolerance in adults is usually caused by insufficient secretion of lactase enzyme to break down lactose, which can be solved by reducing lactose intake or supplementing lactase enzyme. Lactose intolerance in adults may be caused by congenital factors or diseases such as enteritis, which leads to insufficient secretion of lactase in the gastrointestinal tract to break down lactose in a timely manner, which will manifest as lactose intolerance, digestive disorders, and frequent symptoms such as bloating, diarrhea, and loss of appetite. Mild lactose intolerance, reduce the intake of lactose, you can eat low-lactose or no lactose dairy products, choose fermented yogurt, etc., is conducive to digestion and absorption, can relieve the phenomenon of lactose intolerance. If it is more serious, you can take lactase replacement preparation before consuming dairy products to supplement lactase enzyme and promote the digestion of lactose. Adults with lactose intolerance should make dietary adjustments or take lactase enzyme preparations in a timely manner, and receive regular treatment under the guidance of a doctor, which can effectively improve symptoms and quality of life.