The reasons for the sudden decrease in milk production may be that the woman eats less, she is nervous, and the child eats less milk. 1. Reduced food intake: If a woman’s milk supply decreases, it is possible that she has not taken enough food and water recently, which reduces the amount of milk secreted by her body. At this time, the woman can ensure that she has enough sleep, and that she eats enough food and water to increase the secretion of breast milk. 2. Mental stress: The decrease in milk production may be due to the woman’s low mood and mental stress, which may cause a sharp decrease in milk secretion. Therefore, when women are breastfeeding, they should pay attention to keep a good state of mind and try to avoid negative emotions. 3. The child is eating less milk: the woman appeared to reduce the amount of milk, but also may be the child in the anorexia period, eating less milk, the stimulation of the breast is reduced, the breast because of the negative feedback regulation of the milk secretion of the reduction. The sudden decrease in milk production alone cannot be accurately determined, but also needs to be combined with the characteristics of the medical history and other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of the doctor.