HydrationFAQ
Short answers to the questions we hear most, each linking to the full guide
How much water is too much?
For most adults, drinking more than 3–4 liters within a few hours can outpace the kidneys, which excrete roughly 0.8–1 liter per hour. That excess dilutes blood sodium — the condition called hyponatremia — with early warning signs such as frequent clear urination, nausea, and headache; confusion or seizures call for emergency care. Spread your intake through the day rather than drinking large amounts at once. Read the full guide on overhydration warning signs.
Does coffee dehydrate you?
No. Coffee's caffeine has a mild diuretic effect, but regular drinkers develop a tolerance to it, and the water in every cup still counts toward your daily total. Up to 400 mg of caffeine a day (about 4 cups) typically does not cause dehydration in healthy adults. Read the full guide on coffee and hydration.
When can babies drink water?
At around 6 months, in small sips alongside solid foods — guidance the American Academy of Pediatrics also follows. Before then, breast milk or formula supplies all the water a baby needs; extra water can displace nutrients and, in young infants, raise the risk of water intoxication. Read the full guide on water safety for babies.
How much water should I drink with creatine?
There is no fixed number: meet your usual daily target — the one based on your weight, age, and activity — consistently, and drink more for exercise or heat. Creatine draws water into muscle cells, so staying hydrated helps the supplement do its work and reduces cramping and digestive discomfort. Read the full guide on water intake with creatine.
Have a question that is not covered here? Use the water intake calculator for a personalized daily target, or browse the hydration guides for the science behind each topic.