People who are dehydrated often have reduced blood pressure or lower blood volume. When this happens, blood may not reach your brain in the way that it should. This can lead to feelings of dizziness or vertigo.

Does staying hydrated help vertigo?

One thing that sometimes ends up getting missed when you've been having vertigo, feeling dizzy, or having lightheadedness issues, is how much hydration you have been getting. The average individual is well over 50% percent water, so replenishing it is vital.

Can dehydration make you lightheaded and dizzy?

Dehydration. You may become dehydrated if you're overheated, if you aren't eating or drinking enough, or if you're sick. Without enough fluids, the volume of your blood goes down, lowering your blood pressure and keeping your brain from getting enough blood, causing lightheadedness.