Guide · body · 3 min read
Do you actually need eight glasses of water — what to try first, when you are not sure this will work
Eight glasses is a number with no particular evidence behind it. Thirst and urine colour are better guides.
Start here
Six things, in the order that makes the most difference. The first two do most of the work.
Not being sure it will work is a perfectly good reason to try it once.
If you only do one thing from this page, do the first point below. It is first because it removes the most friction for the least effort.
What helps
Tea and coffee count. The idea that they dehydrate you is largely wrong at normal intakes.
Food supplies a meaningful share of your water, especially fruit and vegetables.
Drinking more than you need does not improve skin, concentration or health. It mostly increases trips to the toilet.
What to do when it does not work
Your kidneys are extremely good at telling you what they need. Thirst is a reliable signal for healthy adults.
Pale straw-coloured urine is the simplest check. Dark yellow means drink more; completely clear means you can stop.
There are real exceptions: hot weather, exercise, illness, pregnancy, and some medications. In those cases thirst lags behind need.
Questions people ask
Can you drink too much water?
Yes, though it is rare. Extremely large amounts in a short time can dilute blood sodium, which is dangerous.
Written for people who want the practical version. No accounts, no tracking, no newsletter wall.
If this is not the angle you need, try What to do when you wake at 3am — what nobody tells you, when you only have a few minutes, Using the commute as a boundary between work and home — the version for a bad week, when you want to be left alone or Do you actually need eight glasses of water — the version that fits a real week, when you need something unremarkable.