Drinking water at night is not “forbidden,” but it can reduce sleep quality for some people. The main reason is increased nighttime urination (nocturia), which fragments sleep. For those with reflux or sensitive stomachs, fluids right before bed may worsen discomfort. Still, dehydration is not desirable. A practical approach is to meet most fluid needs during the day, reduce intake 1–2 hours before bedtime, and if needed, take small sips at night.