Nausea and vomiting are commonly experienced by children with serious illnesses. Nausea is not always accompanied by vomiting and children who vomit are not always necessarily nauseous. Understanding the underlying cause or trigger factor may help in choosing the correct anti emetic (anti-vomiting) drugs.
There are many physical causes of nausea and vomiting which act via direct (central) or indirect (peripheral receptor) mechanisms that can stimulate the vomiting centre in the brain. Psychological causes of nausea and vomiting include anxiety, fear and pain. Children also have a sensitive gag reflex and any irritation in the back of the throat may trigger vomiting. It is therefore important to assess the child fully to identify the underlying causes and mechanisms before treating the child.
Note: There are multiple central and peripheral receptors with neurotransmitter pathways that stimulate the vomiting centre in the medulla oblongata of the brain stem. Vomiting is usually triggered by the stimulation of either the vagal afferent receptors in the gut, the vestibular apparatus or direct stimulation of the vomiting centre in the medulla.