4. Being Dehydrated
Skimping on fluids could leave you feeling zonked and unfocused. If the old adage that you need eight cups a day seems daunting, Holwegner says it’s really not as much as you may think. “Everyone super-sizes portions in their heads and this even happens for water. You don’t need a pint-size glass—one cup is actually a small amount.”
Keep a water bottle with you and take sips throughout the day. Juice, herbal tea, broths, and milk will also work to keep you hydrated.