Caffeine Overdose
You're at risk for caffeine overdose when you ingest more than 200 to 300 mg of caffeine (about three 8-oz cups of coffee) in a day. Dizziness,...

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Caffeine overdose may occur when you ingest more than the recommended amount of caffeine, which is usually 200 to 300 mg per day. However, a safe amount of caffeine is different for everyone, as it depends on weight, age, and overall health. This makes it difficult to know the exact amount of caffeine it would take for you to overdose.

Caffeine is a stimulant that can be found in various foods, drinks, and other products—technically, caffeine is actually a drug. It is commonly used to increase wakefulness and alertness. Some of the most popular beverages in the United States, such as coffee, tea, and soda, have significant amounts of caffeine in them.

The chart below shows how much caffeine is typically found in a serving size of some of the more common sources of caffeine, according to the Center for Science in the Public Interest.


Serving Size

Caffeine (mg)


8 oz.


Black Tea

8 oz.



12 oz.


Red Bull

8.3 oz.


Chocolate Bar (Dark)

1.45 oz.


NoDoz Caffeine Tablets

1 tablet


Extra Strength Excedrin

1 tablet


Though a caffeine overdose can result in death in the most severe cases, many patients just notice some unpleasant symptoms until the caffeine is excreted out of the body.

Causes and Risk Factors of Caffeine Overdose

A caffeine overdose occurs when you take in too much caffeine, whether through drinks, foods, or medications that contains this substance. Some people might overdose on 300 mg of caffeine, especially if they rarely ingest this drug. Others can ingest 600 mg or more each day without issue, though this is not usually recommended.

If you rarely consume caffeine, your body may be especially sensitive to this medication, so you are advised to avoid taking in too much at one time. Even if you regularly consume large amounts of caffeine, you should stop consuming it when you feel some of the unpleasant symptoms that accompany caffeine overdose.

What Are the Symptoms of Caffeine Overdose?

There are several types of symptoms that come with this condition. Some symptoms may not immediately alert you to the fact that you have had too much caffeine, since they may not seem serious. For example, you may experience:

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

Other symptoms seem more severe, and call for immediate medical treatment. These more serious symptoms of caffeine overdose include the following:

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

Babies can also suffer from caffeine overdose, including when breast milk contains excessive amounts of the drug. Some of the mild symptoms include nausea and muscles that continually tense and then relax. These symptoms may be accompanied by more serious signs of caffeine overdose, including vomiting, fast breathing, and shock.

If you or a child under your care is experiencing these symptoms, you are advised to seek a doctor’s help immediately for diagnosis and treatment.

Diagnosing Caffeine Overdose

If you let your doctor know that you consumed caffeinated items prior to experiencing the symptoms, he or she may begin treatment for caffeine overdose. If it is not obvious that this is the problem, you may be asked about your symptoms.

In addition, your breathing rate, heartbeat, and blood pressure will all likely be monitored. Your temperature may be taken, and you may be given a urine or blood test to identify the drugs in your system.

Treating Caffeine Overdose

The main point of treatment will be to get the caffeine out of your body while managing the symptoms. You may be given activated charcoal, which is a common remedy for drug overdose. It often prevents the caffeine from going into the gastrointestinal tract.

If the caffeine has already entered the gastrointestinal tract, you may be offered a laxative, or even a gastric lavage, which involves using a tube to wash the contents out of your stomach. Your doctor will likely choose the method that works fastest to get the caffeine out of your body.

During this time, your heart will be monitored through an EKG (electrocardiogram), and you may receive breathing support when necessary.

If you are unsure if you need treatment, you should call Poison Control at 1-800-222-1222 so you can describe your symptoms. If the signs sound severe, you will likely be advised to go to the local hospital for immediate treatment.

If the symptoms are mild, you may be able to wait until the caffeine is no longer in your body, but home treatment does not tend to work for most patients.


Caffeine overdose can usually be treated with no long-term health problems. However, this condition can be deadly, especially for younger patients, such as infants and toddlers. When treatment is given too late, there may be irreversible health problems and even death. You are advised to at least call Poison Control when you suspect a caffeine overdose.


Avoiding the consumption of excessive amounts of caffeine prevent a caffeine overdose. In most cases, you are advised to avoid taking in more than 300 mg per day, and even less if you are particularly sensitive to caffeine.

Written by: Autumn Rivers
Edited by:
Medically Reviewed by: George Krucik, MD
Published: Jul 16, 2012
Published By: Healthline Networks, Inc.
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