A 50-day-old baby who is drowsy may be a normal phenomenon, or it may be caused by calcium deficiency, iron deficiency anemia and other reasons. 1. 50-day-old babies who are drowsy may be a normal physiological phenomenon, which is mostly considered to be caused by the imperfect development of the nervous system of the babies, which may be manifested as a lot of sleep, but the babies’ spirit is normal and feeding is normal, so there is no need to worry too much about this situation, and no need for special interventions. 2. 50-day-old infants who are drowsy, accompanied by crying at night and lack of spirit are usually considered to be caused by calcium deficiency. 3. 3. Iron deficiency anemia, which reduces the number of red blood cells in the blood and causes a chronic lack of oxygen to the brain, may also cause heavy drowsiness, accompanied by pallor and poor appetite. Drowsiness in a 50-day-old baby may also be caused by other factors. If there are other abnormalities, consult a doctor as soon as possible to identify the cause and then give targeted treatment.