2 year old baby drinking milk is usually not harmful, but if allergic to milk or lactose intolerance, as well as drinking too much milk at once, or drinking spoiled milk, etc., it will cause certain harm to the baby’s body, which may result in allergies, diarrhea, etc., and requires timely treatment. 1, allergic to milk: milk contains allogeneic proteins, and 2 year old baby allergic to such substances will appear after drinking milk. Allergy symptoms, such as hives and other symptoms, need to immediately stop drinking milk to avoid allergies again; 2, lactose intolerance: 2 year olds who lack lactase in their bodies, or poor absorption of lactose, etc., after drinking milk will have symptoms of lactose intolerance, can appear nausea, vomiting, bloating, diarrhea, etc., can be adjusted by adjusting the diet, replace the milk without lactose; 3, other: such as drinking too much milk at once, the Symptoms of indigestion such as bloating, diarrhea and abdominal pain can occur. If you drink spoiled or expired milk by mistake, it will also affect the digestive tract and cause diarrhea and other symptoms. 2 year old babies drink milk under normal circumstances, it will not cause harm to themselves, but can also properly supplement the body’s lack of nutrition and protein, calcium, etc. When giving them milk, you need to carefully observe the nature of the milk, as well as the shelf life, if there is precipitation or odor, you need to stop drinking to avoid discomfort.