Guide · body · 3 min read
Do you actually need eight glasses of water — what nobody tells you, when you are doing this for the first time
Eight glasses is a number with no particular evidence behind it. Thirst and urine colour are better guides.
Start here
Most of the usual advice misses the point. What follows is the version that survives contact with a real week.
If this is your first go, stay with the plainest version of the instructions.
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
There are real exceptions: hot weather, exercise, illness, pregnancy, and some medications. In those cases thirst lags behind need.
Pale straw-coloured urine is the simplest check. Dark yellow means drink more; completely clear means you can stop.
Tea and coffee count. The idea that they dehydrate you is largely wrong at normal intakes.
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.
Drinking more than you need does not improve skin, concentration or health. It mostly increases trips to the toilet.
Food supplies a meaningful share of your water, especially fruit and vegetables.
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.
Does coffee dehydrate you?
At normal intakes, no. The diuretic effect is small and does not outweigh the fluid you are taking in.
Written for people who want the practical version. No accounts, no tracking, no newsletter wall.
If this is not the angle you need, try Tired eyes after a long day of screens, for people who have tried everything, on a day that started badly, When the inner voice will not let something go — the short version, when you have just finished work or Why your weekend does not feel like rest — where to start, when you have woken up too early.