What could be the reason for a 3-month-old baby crying and fussing at night?

In general, a 3-month-old infant crying at night may be caused by insufficient feeding, excessive daytime sleep, physical discomfort, lack of comfort and reassurance, or vitamin D deficiency. Appropriate treatment can be selected based on the specific situation. The detailed analysis is as follows:

1. Insufficient Feeding

Nighttime hunger is a common cause of infant crying. Parents can slightly increase the amount of milk before bedtime, which may help reduce nighttime crying.

2. Excessive Daytime Sleep

As infants grow, external stimuli such as the environment, people, or objects may affect them. If an infant sleeps too much during the day, it may lead to nighttime crying. It's important to help infants develop good sleep habits.

3. Physical Discomfort

Infants may cry at night due to physical discomfort. Common causes include wet diapers, abdominal gas, indigestion, etc.

4. Lack of Comfort and Reassurance

If an infant does not receive adequate rest or sufficient comfort during the day, they may become fussy at night. Fatigue and lack of reassurance can lead to emotional instability and increase the likelihood of nighttime crying.

5. Vitamin D Deficiency

Nighttime crying in a 3-month-old infant may be related to calcium deficiency or insufficient vitamin D. Under medical guidance, appropriate calcium and vitamin D supplementation may help improve sleep quality.

If symptoms persist or worsen, it is recommended to seek immediate medical attention for the infant.