I'm asking this question because I overheard someone talking about needing at least two cups of coffee in the morning to "function properly".

Also, they said this while drinking ANOTHER cup of coffee and then went on to have ANOTHER refill ~10-20 minutes later, and all of this was 3-4 hours after they woke up.

Now, I'm no genius, but surely this can't be healthy.

I have several questions regarding the matter:

  1. Can you die from a "coffee overdose"?
  2. What kind of health problems could you get from drinking too much coffee?
  3. How is it possible for someone to need coffee to function, is it like how an addict needs drugs?
  4. If someone who's "addicted" to coffee stops drinking it, would that person suffer from withdrawal symptoms?

Also, for the sake of curiousity, are there any recorded cases of a "coffee overdose"? I've looked around but can't find any.


  • it is normally expected that these four would be separate questions to receive better, to the spot answers. Please see how to ask part of the site in the help.
    – MTSan
    Nov 1, 2018 at 8:19
  • I agree and think this should be closed and reopened as 4 different questions as far as they haven't been asked already (which they mostly have).
    – avocado1
    Nov 1, 2018 at 12:55

3 Answers 3


Caffeine overdoses and even fatalities linked to caffeine overdoses have been reported and a quick google scholar search will show that it is still an active field of research and new cases are being found.

A good overview of caffeine overdose can be found on healthline. Some outakes:

Caffeine overdose may occur if you ingest more than [...] 400mg.

12 oz. black coffee has 260mg of caffeine

Early symptoms:

  • dizziness
  • diarrhea
  • increased thirst
  • insomnia
  • headache
  • fever
  • irritability

Severe symptoms:

  • trouble breathing
  • vomiting
  • hallucinations
  • confusion
  • chest pain
  • irregular or fast heartbeat
  • uncontrollable muscle movements
  • convulsions

Prevention is kinda obvious, but I will quote it for completeness:

To prevent a caffeine overdose, avoid consuming excessive amounts of caffeine. In most cases, you shouldn’t have more than 400 mg of caffeine per day and even less if you’re particularly sensitive to caffeine.

The short answer to your last two questions is that one can be addicted to or dependent on caffeine. In a 2012 study investigating caffeine dependence they found that a staggering 96% of subjects had withdrawal symptoms when taken off caffeine and thus had a physical dependence. The article goes into a lot more detail for each of your questions and has a few more good references. So if you want to investigate further that I would suggest that as a good jumping of point.

  • 1
    Just in terms of the physiology of withdrawl: it would actually be surprising if fewer than 96% had withdrawl symptoms. Physical "dependence" is one way of talking about what happens to the physical receptors in the brain when adapting to caffeine and its blocking adenosine ofrecpetors; how the brain works around this, and what happens when caffeine is withdrawn - there is a physical balance that takes time to rebuid. and it feels like crap too.
    – m.c. von s
    Feb 3, 2019 at 17:38

I am more or less the person you have described. So, let me ease your concerns.

  1. No, one cannot die from coffee overdose. At least, by drinking it. Refer to previous discussion here.
  2. If you are used to drink coffee, apparently, none. If you are not, you may have tachycardia when you drink a lot. Also, may have purgative effects. These are not serious when you used to drink and know your dose.
  3. Not really. Whenever coffee addicts do not take their regular dose, they feel a bit odd, sleepy, sloppy. But this should not really effect their daily rıutine. When they drink coffee, they feel brighter.
  4. This is widely known as caffeine-withdrawal. It may end up with dizziness and headache. But, if someone insists on not drinking coffee, they disappear.

Please, check the tag for more. There are many other topics yu might find useful.

  • To 3.: Caffeine is in fact a psychoactive drug with different, very complex and still not really understood mechanisms of actions. But it does not create addiction in the sense that it would drive you to compulsive behavior as alcohol, cigarettes, marihuana or many other drugs would do. It does create mild physical dependence though with withdrawal symptoms that typically last a day or two. That's why some people "need" coffee in the morning to feel more energetic.
    – avocado1
    Nov 1, 2018 at 13:03
  • just to rif on what avocado1 says here - "needing" coffee in the morning to feel energetic may also have nothing much to do with the properties like caffeine in coffee - it can also be (1) habit (2) being tired/underslept - and so using a stimulant to fight those natural signals to get more sleep - rahter than drugs.
    – m.c. von s
    Feb 3, 2019 at 17:40

A sense of anxiety. If you experience constant anxiety, anxiety, frequent heartbeat, sweating palms, you may have an overdose of caffeine. These symptoms are caused by the fact that caffeine activates the adrenal glands, which is accompanied by the flow of a huge amount of stress hormones into the blood.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.