You may love caffeine’s feel-good effects, but overdosing can harm your health. Here’s how to tell if you’re overdoing it
1. You hit an afternoon slump.
If you can’t get through the day without a Diet Coke fix, you may be hooked on the caffeine. "There is about as much caffeine in one can of Diet Coke as there is in a shot of espresso," says David J. Clayton, MD, author of The Healthy Guide to Unhealthy Living. Having a few cans a day could leave you feeling high, and then low when you come down from the caffeine buzz." Besides triggering major dips in energy, the acidity in soda can damage tooth enamel if sipped daily. Limit your Diet Cokes to one a day to avoid hitting a wall in the afternoon, and brush your teeth if possible after drinking soda to help reduce its enamel-eroding effects.
2. You’re peeing orange.
Urine that is dark yellow or orange is a telltale sign of dehydration. "Coffee is actually a diuretic that can lead to dehydration by increasing the amount you urinate so you lose too much body fluids," says Amy Gross, MPH, RD, CDN and a clinical dietician at New York Presbyterian Hospital. Caffeine usually doesn’t trigger dehydration until after you’ve had about 500 mg, so you should be safe if you stick to a cup or two of coffee a day.
3. You can’t sleep.
"Caffeine takes about 45 minutes to 1 hour to get absorbed and has a very long half-life, meaning it lingers in the body for several hours and can affect your sleep cycle," says Molly Morgan, R.D., owner of Creative Nutrition Solutions in Vestal, New York, and author of The Skinny Rules. If it takes you longer than 30 minutes to doze off at night, you might try cutting out caffeine once the clock strikes 12 p.m. to see if it helps you get more restful sleep. That applies to all caffeine-containing substances: Sipping green or Chai tea may be a sleep stealer, too, because both beverages contain caffeine. Also keep in mind that decaf coffee and decaf tea are not caffeine-free: both have about one-third the amount of caffeine as the regular kind.
4. You feel anxious.
Sweaty palms, a racing heart, restlessness, and feeling jittery are all clues that you’ve overdosed on caffeine. "Caffeine can exacerbate stress and depression because it interferes with a tranquilizing neurotransmitter chemical in the brain called adenosine," says Palinski. Caffeine can also act as a stimulant that triggers the adrenal gland to excrete more stress hormones like adrenaline, which can increase heart rate, making you feel more anxious.
5. You have heartburn.
Acid reflux happens when the muscle at the end of the esophagus, known as the lower esophageal sphincter, allows food and stomach acid to come back up, causing a burning feeling under your chest. If this happens to you, caffeine could be a culprit. "Caffeine relaxes esophageal sphincter, which allows acid to come up in the throat," says Gross. Try cutting out caffeine altogether to see if it soothes your throat.