The usual causes of dehydration are a lot of diarrhoea and vomiting.
Dehydration can also occur if you do not eat or drink much during an illness or if you do
not drink enough during or after strenuous exercise. Medications that cause fluid loss to
control excess body fluid (diuretics) are a common long-term cause.
Although anyone can become dehydrated, those who become dehydrated the
most easily are:
How does dehydration occur?
