Why Does My Baby Sweat Excessively While Sleeping?

New mothers often notice that their babies sweat excessively during sleep and become puzzled and anxious—unsure of the cause or how to address it. So, what exactly causes excessive sweating in sleeping infants? Below, we provide a detailed explanation.

Why Do Babies Sweat Excessively During Sleep?

1. High Body Water Content

Babies appear especially plump and dewy because their bodies contain significantly more water than adults. In newborns, water accounts for up to 85% of total body weight. Additionally, infants have an abundant network of capillaries, making them prone to sweating.

2. Immature Nervous System Development

This refers specifically to incomplete development of the autonomic nervous system. All organs and neural pathways in infants are still maturing and not yet fully functional. Consequently, the autonomic nervous system—which regulates sweating—is relatively weak, impairing the infant’s ability to self-regulate body temperature and leading to increased perspiration.

3. High Metabolic Rate

Infants have exceptionally active metabolism. As long as they are awake, their metabolic processes operate continuously—naturally resulting in strong sweating capacity.

4. Excessive Nutrition

As the apple of their parents’ eyes, many infants receive overfeeding with nutrient-dense foods out of concern for inadequate nutrition. This leads to nutritional excess. After consuming high-calorie foods—such as meat, dairy, and eggs—infants are more likely to sweat profusely.

5. Rickets

Excessive sweating is a hallmark symptom of rickets. Other manifestations include nighttime crying, loud vocalizations, pigeon chest (pectus carinatum), and bowlegs (genu varum). Rickets primarily results from vitamin D deficiency. However, most parents begin supplementing vitamin D and calcium shortly after birth, making rickets-related pathological sweating relatively uncommon.

The above outlines the main reasons behind excessive sweating during infant sleep. Since each case varies, individualized assessment is essential—for example, adjusting dietary balance if nutritional excess is suspected. With patient, attentive care, your baby will thrive and grow healthily. We hope this information proves helpful—and wish you joy and well-being!