Caffeine Overdose Symptoms: Signs, Cases, Prevention


Top 10 Caffeine Overdose Symptoms

Here are the usual symptoms in order from the first ones to be experienced to the more severe, later stage consequences.

  1. Jitters, Restlessness, and Nervousness
  2. Increased heartbeat
  3. Nausea
  4. Anxiety
  5. Heart palpitations (cardiac arrhythmia)
  6. Insomnia
  7. Sweating
  8. Dizziness
  9. Vomiting
  10. Cardiac arrest

There can be many common symptoms that indicate too much caffeine consumption, but these are the most prevalent.

These symptoms should be recognized and further caffeine intake should be stopped to avoid more serious and even life-threatening symptoms.

Ingesting massive doses of caffeine all at once is particularly dangerous as it doesn’t give your body time to react. Overdose symptoms serve as an early warning system.

Caffeine’s major effects are experienced for at least 4 hours.

  • This is longer for those sensitive to caffeine.
  • This is longer with extremely large doses.
  • This is based on the half-life of caffeine which is 4-6 hours.

It’s hard to pinpoint an amount of caffeine that will cause these caffeine overdose symptoms as people have different tolerance levels.

Are You Addicted to Caffeine?

You may want to consider quitting. A detox program like Wean Caffeine is scientifically designed to help you quit caffeine gradually and safely. This prevents the horrible withdrawal most people experience when quitting.

Prevention: Maximum Daily Intake

You can prevent caffeine overdose by adhering to the recommended safe dosage guidelines.

Generally, a dose between 250-500mg (check caffeine amounts here) could produce some of the above mild to moderate symptoms, especially in those with no tolerance of high caffeine sensitivity.

Those with a caffeine allergy or sensitivity could have severe symptoms even after a very small dose.

Click here to find out how much of a popular drink would it take for you to overdose.

DSM-5 Criteria

Insomnia is a common symptom of too much caffeine

Caffeine Intoxication is now included in the DSM-5 physicians manual.

The official diagnosis can be made when any 5 of the following symptoms are present: restlessness, nervousness, excitement, insomnia, flushed face, diuresis (you keep passing urine), gastrointestinal disturbance (upset tummy, diarrhea), muscle twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia, periods of inexhaustibility, or psychomotor agitation.

The DSM-5 now also lists Caffeine Withdrawal as a mental disorder. Sufferers can experience withdrawal symptoms when ceasing caffeine intake.

Caffeine Addiction as a disorder was rejected from the next version of the manual.

Reducing the Impact of Caffeine

There is some research indicating products that contain rutaecarpine can actually reduce the impact of caffeine’s side effects. They do this by assisting with caffeine metabolism*. Learn more here.

Caffeine Overdose Documented Cases

Caffeine overdose does happen and has been documented. Here are some of the more recent cases resulting in death or hospitalization;

  • 19-year-old James Stone dies after taking 25 to 30 No Doz pills in 2007. (at least 2.5 grams of caffeine)
  • 40 Seagulls die from caffeine overdose in Canada this year from eating used coffee grinds.
  • 17-year-old Jasmine Willis, a Durham, UK waitress overdosed by drinking 7 double espressos in 2007. She was taken to the hospital but recovered soon after. (that’s roughly 1.078 grams)
  • In the late 1990’s an Australian woman, with a heart condition died after consuming a guarana based shot from her local health food store. This product is no longer on the market. (10g/liter, ok that’s just nuts!)
  • 2010 a 23-year-old British man from Mansfield, England died after taking to 2 spoonfuls of pure caffeine powder washed down by an energy drink at a party. His death was ruled accidental.
  • 2011 Fourteen-year-old Anais Fournier, died after she consumed two 24 ounce Monsters (480mg of caffeine) in a 24 hour period. The cause of death was a heart arrhythmia due to caffeine toxicity.  There seem to be some conflicting stories as to how much she really consumed and this seems true since 480mg in a 24 hour period isn’t a toxic amount. Update October 2012: Her parents are suing Monster Energy for wrongful death although the girl did have a known pre-existing heart condition.
  • 2012 The FDA is investigating Monster Energy since the energy drink has been linked to five deaths over the past year.
  • 2013: According to the Substance Abuse and Mental Health Services Administration, energy drink-related ER visits have doubled in the last 4 years, however, 42% of these visits involved caffeine in combination with other drugs such as alcohol or other narcotics. src.
  • 2013 a New Zealand woman died from cardiac arrhythmia associated with her 10 liter/day Coca-Cola habit. She also smoked 30 cigarettes a day and barely ate. Caffeine was a contributing factor, but the 900-1000mg daily dose wasn’t the only factor. src.
  • 2013 A mother is suing Monster Energy for the death of her 19-year-old son, Alex Morris, after he died of cardiac arrest. She claims that he drank two 16 ounce Monsters the day before his death and at least two a day for the 3 years preceding his death. A California Coroner’s office reported that he died from cardiomyopathy and cardiac arrhythmia.
  • October 2013: John Jackson from the UK dies after eating a whole tin of HERO Energy Mints. Each tin contains 12 mints, so he consumed 984mg of caffeine. He also had cirrhosis of the liver, which prevented him from processing the caffeine properly allowing it to build up in his bloodstream to lethal levels. (src.)
  • March 2014: A 14-year-old boy from Norway was hospitalized with kidney failure after drinking 4 liters of a caffeine-laced energy drink while gaming for 16 hours straight. This would be around 1,280mg of caffeine if he was consuming a “Red Bull” like energy drink. (src.)
  • September 2014: A Tennessee man was taken to the hospital after consuming 20 caffeine pills to “test the limits of his body” according to what the man told the paramedics. He ingested 4000 mg of caffeine at once. src.

Caffeine Overdose Facts

too-much-caffeineLuckily for us, we have mechanisms built into the human body that let us know we’ve had enough of something.

This is true with caffeine overdose. Well before we are at a toxic level we experience side effects that prevent us from consuming more, i.e. nausea and vomiting.

This means that before the 149 or so cans of Red Bull that it would take to kill an average adult male, vomiting would most certainly happen.

For most, that would happen after about can number 5!

It’s important to note, however, that caffeine is a drug and should be respected and not abused. Since some people have extremely low tolerance to caffeine, they could  – in theory – overdose quite easily.

How to Know If You’ve Overdosed

Most people feel the “jitters” first – a sensation of tremors or shaking.

This is your signal to stop consuming caffeine for the day.

You should also be aware of the caffeine levels in what you are drinking. Please consult the caffeine database. Some of the caffeine amounts will surprise you.

If you are finding you are often tired after consuming caffeine this is a sign that you need to change your long-term habits and could indicate adrenal fatigue.

The bottom line is to be aware of what you are consuming.

How common is caffeine overdose?

With the plethora of caffeinated products in the marketplace, one could assume that overdosing on caffeine is quite common.

If we look at the statistics from The American Association of Poison Control Centers we find that, while it does exist, it isn’t as common as we might think.

In fact, overdosing on Tylenol is a lot more common than overdosing on caffeine.

Since caffeine is consumed so widely, there are a lot of half-truths, hearsay, urban legends, media hype, and even fiction.

It’s good to take an honest look at the subject and try to put all of the information into perspective. We can then determine if caffeine should be in the same category as other drug overdoses are.

Get Help Quitting Caffeine

Reduce your caffeine intake without pain and discomfort.

See our new 10-step plan
  • ej

    this article was really helpful. incredibly i didn’t know anything about caffeine overdoes until i drank a half jar of coffee with 2 coke bottles within 12mins. and that’s what brought me here. that was yesterday. thought i was going to die. still feeling ill but allot wiser. thank you.

  • Kevin

    I overdosed last night, idowned a bottle of mio energy drink mix and 2 monsters. I experienced all the symptoms ecluding cardiac arrest luckily hahah. They gave me an iv and 6 shots, i was out after 5 hours.My heart rate was at 139-147bpm while the average is 60-90bpm.

  • Kevin

    and i was taken to the E.R.
    I read up on the sight and i downed 1400mg in caffeine

  • Jury

    My friend consumes a lot of cafeine and he’s addicted to it now.,wat should i do to stop him.,any medical remedy?

  • Paige

    Is it possible to suddenly become allergic to caffeine? I used to drink coffee, quite often, cokes, red bulls, never liked monster but loved the Blue Agave full throttle, and power flavored rip it. All of a sudden anything with caffeine makes me jittery and feel like my skin is crawling I want to drink a frozen coffee drink so bad but when I do I feel like total garbage after and can’t sit still or catch my breath. Why?

  • jacqui

    I had to stay up driving for 24 hrs and took 5 200 mg caffeine pills. Also downed 1 rockstar recovery and a 5 hr energy- extra strength all within a 3 hr window. I ended up throwing up the 5 hr energy but i still feel sooo nauseated and have had constant diarrhea and frequent urination. Would not recommend taking this much! Holy crap i may go to the hospital. I feel sooo sick.bad idea.

  • April

    I took a combination of yellow jackets, 5 hour energy, red bulls and no doz in a 24 hour period while drivimg from colorado to georgia. When i arrived to georgia i passed out. I woke up with a knot on my head, i bit my tongue in half, i peed my pants, and i couldnt remember anything. I have not touched an energy drink since.

  • Elle


    Have you ever had your blood sugar levels tested?

  • ted

    Yes Paige you can, we wrote about caffeine allergies here.

  • Renee

    Thanks. this is really helpful. I drank a lot of caffeine today and i’m a fifteen year old girl. I still feel a bit nauseated but i’m sure i’ll be fine. thanks.

  • sam

    I never realized how dangerous this was until it happened to me. I consumed more than 4 of those 5 hour energys, as well as 5 cups of coffee in a 4 hour period. I was on a long drive and determined to make it 7 more hours… I ended up in the hospital. If I had taken any more and not recieved medical attention I could have died. This is no joke, be careful.

  • Thomas A

    I overdosed yesterday afternoon after downing a large bottle (about 600mL or 20 fl oz) of extremely strong and bitter Vietnamese iced coffee in record time. Normally I can easily cope with small amounts of coffee but this time I was stupid enough to drink not only a large amount, but I also drank too quickly.

    At first I noticed no symptoms, but barely an hour after finishing the coffee I became irritable so I decided to go home early from work. On my way back, I nearly became delirious and was afraid I wouldn’t even make it to the hospital. An hour later, I checked myself into the hospital and an ECG and ultrasound of my heart rate were performed. Given my age and relatively good physical shape, my resting heart rate should be about 60-70 bpm but I was averaging 105 bpm thus suffering from sinus tachycardia. At the same time, I was suffering anxiety, confusion, irritability and tremors. 24 hours later and my heart beat lowered down to 94 bpm and is now probably around 80 rpm or so, roughly 30 hours after the crisis started.

    I never realized the serious dangers of caffeine overdose which could lead to cardiac arrest or even death in extreme cases until yesterday, which was a major wake-up call for me. I estimate that with just 1L (0.26 US gallons) of the same coffee, I probably would have ended up suffering a heart attack and roughly 3 bottles (or possibly less) would have likely caused death due to complications arising from a severly irregular and fast heart beat.

  • julia

    two weeks ago I had coffein overdose just by drinking two large coffee from Macdonald’s . I could NOT breath and it already happened few times to me before but I did not know it could kill me untill two weeks ago.

  • Annkiera

    This was really helpful, thanks!

  • Nic

    Very helpful article. I had given up all caffine except for 1 8oz cup of coffee in the am, 3 months ago due to TMJ. Today I ate lunch with friends and consumed strong iced tea and now feel very strange….too much caffine!!!

  • James

    Very interesting and informative article. I habitually consume caffeine in quantities > 700mg per day, so naturally I have a somewhat higher tolerance for it than most people. However, a few days ago I went on a “caffeine binge” (I had been on detox for about 3-4 weeks). 3 monsters, 1 mega monster, and 2 amps. Being that I hadn’t consumed caffeine in a while, I was naturally a little more sensitive than I would normally be. I knew I could overdose on caffeine, but I didn’t expect it to happen to me. I looked up the symptoms (here) and decided I should go to the hospital. I did, and it turned out my heart rate was fluctuating between 125 and 135 bpm. They treated me and I’m nearly recovered, but I never fully realized the negative effects caffeine could have on my body. Thanks so much!

  • Kat

    this report cant be serious i used to drink at least 4 or more monsters/red bulls a day. and ive had at least possibly 6 or 7 monsters already today alone. ive expierenced none of these symptoms.

  • maria

    i went on a cruise to the anacortes and i drank 2 monsters 7 cups of coffie a caramel macciatio with 2 extra shots a caramel frapee and a bunch of koolaid and i felt like crap-.- it pretty much sucked, but luckly i didnt have to go to the hospital

  • ted

    People respond to caffeine differently, what might be fine for you, could send someone else to the hospital.

  • Yue

    “40 Seagulls die from caffeine overdose in Canada this year from eating used coffee grinds. (ok, that one is just funny, sorry)”

    Yes, it’s always funny when life is needlessly snuffed out. It’s only more hilarious when hungry scavengers perish after thinking that they found a meal.

    If you want a death that’s truly comedic, please kill yourself and do the world a great service in the process.

Last Modified: November 13, 2017


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