Question
What causes children to sweat with blood and feel weak while sleeping?
Answer
It is normal for children to sweat while sleeping, as they have more developed sweat glands. The sweat glands are controlled by the vagus nerve (a branch of the parasympathetic nervous system). When asleep, the vagus nerve becomes excited, leading to excessive sweating, usually more on the head and face, but this usually subsides within one to two hours after sleep. If sweating continues throughout the night and is quite heavy, it may indicate a dysfunction in the vagus nerve, and in some cases, it could be due to a calcium deficiency.