That's because your body needs to be properly hydrated to feel energized and function optimally. Here's what happens when you're dehydrated: As dehydration sets in, your blood pressure drops, leading to poor circulation and reduced blood flow to your brain. This causes feelings of sleepiness.

Can dehydration make you tired all the time?

Lack of water can cause you to experience periods of fatigue and low energy as your body tries to function without enough water. If you're constantly feeling sluggish and tired despite getting a quality night's sleep, you may need to boost your water intake.

Can not drinking enough water cause tiredness?

How Lack of Water Affects You. More than half your body weight comes from water. So if your levels are off, it can show up in a surprising number of ways. Mild dehydration can make you feel tired, give you a headache, and affect your mood and focus.