Anyone who spends time around children knows that vomiting is unfortunately not an unusual activity for them. Vomiting in children is usually caused by a virus, over-exertion/excitement, or motion sickness, and is not normally a reason for significant medical concern. It can be, however, worrisome to the child and a messy problem for you. By recognizing the common causes and acting proactively against nausea and other triggers, you stand a much better chance of preventing vomiting in children.