What to Do When You’ve Had Too Much Caffeine

Vanessa Raymond Fact Checked
© Jamie Grill Atlas / Stocksy United

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 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.

“While the response to caffeine varies, 400 milligrams or above is generally the amount considered excessive for adults,” says Arun Sridhar, M.B.B.S., M.P.H., a cardiac electrophysiologist and specialist in heart rhythm disorders at UW Medicine Heart Institute.

And it’s important to know that the maximum tolerated dose of caffeine differs between adults and children.

“Children weigh less and are more prone to its effects. So we caution against overuse in kids,” says Sridhar.

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.

“Rather than a universal set point for how much is too much, it’s when you take in an out-of-the-ordinary amount for you that you experience bad effects,” says Sridhar.

It’s not only coffee that can pole vault you over your own personal caffeine set point but also snack bars, soda, bottled water, energy drinks or over-the-counter or prescription headache or PMS medications, all of which can contain caffeine.

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. They range from relatively mild symptoms like sweating and restlessness to uncomfortable symptoms like nausea, diarrhea and anxiety.

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.

A newsletter that’s good for your health

Subscribe me, please

The effects of caffeine on your heart

Caffeine stimulates your heart rate and gives a temporary boost to 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.

“On a high caffeine dose, people will feel a lot of skipped beats, thumping or a noticeably fast heart rate. If your heart rate is irregular or stuck at a very high rate, if your symptoms just feel overwhelming or if you are dizzy or faint, then you should go to the emergency room,” says Sridhar.

That’s because dizziness can indicate that your body is not pumping enough blood to your brain.

If your symptoms are not overwhelming and don’t include dizziness, but you’re still concerned, then you can make an appointment with a doctor to get checked out instead, he says.

You should also 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.

“Jitteriness feels like anxiety to someone who is primed that way,” says Sridhar.

Any heart symptoms you experience can add to this anxiety.

“When people feel their heart thumping hard, this tends to increase their anxiety and can contribute to a feeling of panic,” says Sridhar.

So if you have a predisposition to anxiety or panic attacks, caffeine may exacerbate those feelings. That means that 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. And this could take 4 to 6 hours, says Sridhar, unless you’re one of the unlucky few who are caffeine-sensitive, in which case you may have to wait much longer. Sigh.

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

No more caffeine. Don’t consume any more caffeine today. Seems like a statement of the obvious, but be sure you don’t absentmindedly nosh on your usual mid-afternoon 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 that your breathing is fast and shallow — and that will only further increase your anxiety. Take slow, deep, deliberate breaths to bring your breathing back to normal and reduce anxiety.

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.

“Hopefully you’ll remember the unpleasantness the next time around and say no to that extra cup of coffee,” says Sridhar. “Caffeine is best in moderation.”