5 Signs you've had too much caffeine

You know you’re a caffeine addict when your eyes won’t open before you’ve taken your first sip of morning Joe, or if your co-workers call you “Crabby” when you skip your afternoon Diet Coke. While the best part of waking up may indeed be Folgers in your cup, being over-caffeinated may also be harmful. “Studies have found that some caffeine can improve mental acuity and performance throughout the day, but too much caffeine can negatively impact your mood, energy, and even health,” says Erin Palinski, RD, CDE, CPT, who has a private practice in New Jersey.


Enjoying a latte probably won’t hurt you, and may even have surprising health benefits such as lowering your risk of Alzheimer’s disease. Just keep in mind that—as with most delicious things in life—it is possible to have too much of a good thing.
“Some research has linked high doses of coffee to infertility and increased risk of hip fractures in older women,” says Keri M. Gans, MS, RD, CDN and author of The Small Change Diet. “If you stop drinking coffee abruptly, you may experience irritability, fatigue, headaches, and even depression.”

So how much caffeine is too much? The American Dietetic Association recommends having no more than 300 mg a day, or the amount in about two or three 8-ounce cups of coffee. Even if you’re not a java lover, you may be getting caffeine from sneaky sources unknowingly: Sports drinks, supplements, and even certain medications contain caffeine. Sneaky sources of caffeine include:

• 2 tablets Excedrin for headaches; 130 mg
• Vital Energy water; 150 mg
• 16-ounce Snapple ice tea; 42 mg
• 1 cup Ben & Jerry’s No Fat Fudge Frozen Yogurt; 85 mg
• 1 cup Dannon Coffee Yogurt; 45 mg
• Barq’s Root Beer; 22 mg
• Hershey’s chocolate bar, 12 mg 

For perspective, one 8-ounce cup of coffee can have anywhere from 125 to 150 mg.
While caffeine’s effects may be different for different people, here are some common warning signs that you may have overdosed.


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.