Flushes Toxins
Overnight, your body’s natural detox systems (mainly the liver and kidneys) have been working. Hydration first thing helps these organs move waste out faster.
Improves Alertness
Mild dehydration can make you feel sluggish and foggy. A glass of water can improve brain function, mood, and focus early in the day.

Extra Tip:

Room-temperature or slightly warm water can be gentler on an empty stomach than ice-cold water.
Adding lemon can give you vitamin C and a fresher taste, but plain water works just fine.