What to Do When You’ve Had Too Much Caffeine

You were just trying to get the wake-up job done and now this. That joyful lift that you felt at 7 a.m. has turned south. Deep south. Maybe that espresso chaser wasn’t such a good idea after all.

Your eyelid is twitching, your heart is going thumpa thumpa and your leg is doing the cha-cha.

Yep, another overcaffeinated Monday.

We get it. Over-the-top coffee consumption is how you tolerate a day in the life. But now what? 

How much caffeine is too much 

Everybody metabolizes caffeine differently. That’s because your genetics, age, weight, tolerance and liver all play a role in how quickly you process caffeine. 

“Most people’s caffeine intake is probably equivalent to about 1.5 to 2 cups of coffee per day,” says Dr. Beixin Julie He, a cardiac electrophysiologist at UW Medicine Heart Institute.  

Which, though less than the recommended maximum daily caffeine consumption of 400mg (about 4 cups of coffee), is still a lot of caffeine, according to many experts. And remember, one cup is 8 ounces or about an average mug of coffee. In Starbucks terms, we're saying a short (8 ounces) is one cup, a grande (16 ounces) would be two cups and a trenta (31 ounces) may give you some jitters.  

Something else to remember? The maximum dose of caffeine mentioned above is for adults. Because children weigh less, they’re more prone to its effects and should ingest much less caffeine — which means curbing their soda and chocolate intake.  

It’s tough to standardize the measurement of caffeine in coffee because it depends on bean origin, flavor, roast and grind, not to mention water temperature, brewing time and, well, you get the idea. But a typical cup of brewed coffee has caffeine levels from 65 to 120 milligrams, while a shot of espresso ranges from 30 to 50 milligrams. 

As mentioned earlier, everyone’s tolerance is going to vary based on the way they personally react to caffeine. There isn’t a universal amount of caffeine that is “bad” for everyone, it’s just about how much your body can handle before going haywire. 

Plus, it’s not only coffee that can pole vault you over your own personal caffeine set point — there’s also often caffeine in: 

• tea 
• snack bars 
• soda 
• bottled water 
• energy drinks 
• over-the-counter or prescription headache medication
• PMS medications 

The symptoms of too much caffeine 

Caffeine is a stimulant. That’s why it helps wake you up in the morning. And it’s a big part of why you like it. 

Aside from that jittery leg, there are other signs of too much caffeine.  

“Symptoms of too much caffeine include restlessness, shakiness, rapid or irregular heartbeats, headache, irritability and insomnia,” says Dr. He.  

The good news is that most of these symptoms, unpleasant as they are, won’t endanger your life. Cardiovascular symptoms, on the other hand, require vigilance. 

The effects of caffeine on your heart 

Caffeine stimulates your heart rate and temporarily boosts your blood pressure. And for most people this isn’t a problem.

But in anyone with a pre-existing heart condition (known or not), excessive caffeine can trigger fast and irregular heart rhythms, which could lead to sudden cardiac arrest.

So, if you have an irregular heartbeat, feel dizzy or faint, a visit to the emergency room is in order. Dizziness can indicate your body is not pumping enough blood to your brain.

You can also make an appointment with your primary care doctor to get looked at if your symptoms aren’t too overwhelming (and don’t include dizziness) but are still worrying you.

And discuss your caffeine intake with a doctor if you have a pre-existing arrhythmia or seizure disorder, as caffeine can trigger these conditions.

Caffeine can contribute to anxiety 

It’s caffeine’s effect on your nervous system that produces the jitters. But if you have a predisposition to anxiety, that jitteriness can make you feel even more anxious. 

Especially for people already dealing with anxiety, “excess caffeine intake can contribute to increased anxiety and unease,” says Dr. He.  

Any heart symptoms you experience can add to this anxiety, especially because when people feel their heart thumping, it can only increase their concern. 

So if you are predisposed to anxiety or panic attacks, caffeine may exacerbate those feelings. That means you’re probably not having a heart attack but having a hard time telling the difference between a heart attack and anxiety. 

What you can do to feel better 

Like recovering from a hangover, you’ll have to wait out your caffeine overdose to get over it completely, generally around 4 to 6 hours.

But while you’re waiting (anxiously), here are a few things that might help. 

No more caffeine. Don’t consume any more caffeine today, not to state the obvious. And don’t absentmindedly nosh on your usual midafternoon chocolate-covered snack bar by mistake. 

Drink plenty of water. Caffeine is a diuretic, which means that you need to drink extra water to make up for what you’re peeing out. You don’t want to add dehydration to the unpleasantness. 

Replace electrolytes. If you have been sick to your stomach or have diarrhea, you’re losing not only water but also electrolytes. You can replace those with an electrolyte replacement solution like Pedialyte.

Take a walk. If you feel a lot of pent-up energy, take a walk to expend some of it. But if you notice anything unusual happening to your heart rate — like a sudden rapid increase — then stop.

Practice deep breathing. If you’re anxious, chances are your breathing is fast and shallow — which will further increase your anxiety. Take slow, deep, deliberate breaths to bring your breathing back to normal and reduce anxiety.

Dr. He also recommends meditation and practicing healthy sleep habits as two additional ways to combat your caffeine overkill.

On the bright side, unless you have a cardiac side-effect, chances are you will recover with no permanent damage. So don’t beat yourself up too badly.

And like most things in life, the key to caffeine is to not overdo it. 

“In general, moderation promotes a balanced, healthy lifestyle,” says Dr. He.  

Maybe we’ll skip that afternoon americano — at least for today.  

Editor's Note: This article was originally published on February 18, 2019. It has been reviewed and updated with new info. Vanessa Raymond and Heather Logue contributed to this article.