CHICAGO (CBS) — If you feel headachey and tired or maybe you’re gaining some weight, your problem could be water…or a lack of it.

While we all know we should drink water, many of us don’t drink enough.

READ MORE: New Illinois Laws To Protect Sex Crime Victims' Privacy Take Effect Jan. 1

NorthShore University HealthSystem, Emergency Medicine physician, Dr. Brigham Temple said “We see patients for dehydration almost every day.”

He said it’s especially a problem this time of year.

Dr. Temple said “some symptoms of dehydration would be feeling lightheaded, headaches, initially sweating profusely.”

But some people experience vague symptoms all year round, sort of a constant state of dehydration.

Northwestern Memorial Hospital Urologist Dr. Robert Nadler said “It can explain chronic headaches, fatigue, difficulty sleeping.”

The afternoon headache – you think might be from lack of caffeine – could be your body telling you to drink the clear stuff.
And doctors tell us a lack of water could even be the reason you aren’t losing weight.

Dr. Temple said “Drinking a full glass of water will often send a signal to your body that you’re satisfied and therefore you’ll maybe forgo grabbing that candy bar or those cookies.”

READ MORE: Chicago Weather: Cloudy Overnight With Snow Flurries For Some

Dr. Temple said most people should follow the 8 by 8 rule. 8… 8 ounce glasses of water a day.

For the average person weighing between 150 and 170 pounds soda, coffee, tea and even food — give us some fluid, but you still need water.

So, for the average person that maybe goes to work every day and drinks coffee until noon they need to be drinking more water?

Dr. Temple said “That’s right, so trying to hydrate yourself all day with coffee is not going to get the total amount of water you need.”

Marcella Lowell, who drinks a lot of water told us it does make a difference.

“I just feel better hydrated, like I don’t get headaches as easily.”

Dr. Nadler said if you aren’t sure how hydrated you are– look down.

He said “When you’re dehydrated your urine is going to be a dark yellow or almost orange color. When you’re well hydrated it’s going to be completely clear.”

Something to consider– 80 percent of people who form kidney stones are dehydrated.

MORE NEWS: View Live Radar

And remember, you need to drink extra water when you exercise, about 8 ounces for every 30 minutes to an hour of activity.