The 20-month-old baby always crying may be related to physiological factors such as hunger, and may also be related to pathological factors such as intestinal cramps, calcium deficiency and so on. 1. Physiological factors: if the baby will cry when hungry, it can be relieved by eating, and the child should be guided to develop good eating habits. 2. Intestinal cramps: intestinal cramps may be related to dietary factors, hunger, cold, etc., can be manifested as a sudden onset of abdominal pain, so there will be crying, etc., and in severe cases, you can use antispasmodic drugs, such as atropine, etc. to relieve. 3. Calcium deficiency: babies are prone to cry at night when calcium deficiency occurs, you can take calcium gluconate, vitamin D drops and other relief. If the baby crying phenomenon is frequent, go to the hospital in time to check the diagnosis, the use of drugs need to follow the doctor’s instructions.