Caffeine Overdose Symptoms. How much Caffeine is too Much

Caffeine is a mild stimulant to the central nervous system. It sends an energy impulse to the brain which helps to increase physical endurance, improve mood,  cognitive abilities such as memory and focus.

At the same time, it is important to note that excessive  amount of caffeine may cause various side effects (or even caffeine overdose symptoms). Let's find out how to calculate healthy amount of caffeine and what is waiting for you (whether there  is life) after caffeine overdose.

What is caffeine used for. The main sources of caffeine

In order to calculate an average amount of caffeine, it is important to know sources of caffeine.

  • Caffeine is widely used in the pharmaceutics as a component in  more than 1,000 medicines sold in pharmacies on or without prescription. In addition to caffeine pills, various headache and migraine medications contain caffeine as an integral ingredient.
  • Of course, caffeine is contained  in tea leaves and coffee beans – so-called natural sources of caffeine. Interestingly, coffee is the most consumed breakfast drink in the United States, it is the main natural  source of caffeine for adults.
  • Caffeine is added to some soft drinks and food products for flavor; take coffee flavored chocolate and energy drinks as examples. Soft drinks are the main source of caffeine for young coffee drinkers  aged 2 to 17.

We’d recommend to read labels and stickers to be aware if caffeine is a component in these products. It will prevent you from unwanted effects of too much caffeine or caffeine overdose.

Recommended caffeine intake

The basic rules of caffeine consumption are moderation and common sense. According to the leading medical and scientific experts, 200-300 mg of caffeine per day does not result in adverse effects to the body and does not threaten health, being safe for the healthiest adults. As a rule, safe caffeine intake is equivalent to 2 or 3 cups of coffee.

  • Currently, an average daily amount of caffeine in the diet of an adult is about 200 milligrams.
  • For adolescents 100mg of caffeine per day is a normal caffeine intake.
  • Wise caffeine intake for children is about a quarter of that amount, i.e. 50 mg of caffeine per day.

Any dose higher than listed below is excessive which causes a variety of negative side effects. What happens when too much caffeine is ingested we’ll be described  in the next chapter.

How much caffeine is too much: symptoms of caffeine overdose

Excessive caffeine consumption leads to side effects. Some of them appear instantly, others are felt in the process of metabolism. Here you can read about short- and long-term effects of caffeine.

The most common symptoms of caffeine overdose that require emergent care:

  • Dizziness: disorientation in space, blackout. Usually it occurs immediately after  consumption of extra  doses of caffeine.
  • Irregular or rapid heartbeat, pain in the heart area. Since caffeine is a stimulant, it affects the heart which begins to react to caffeine 15 minutes after you drink coffee or energy drinks.
  • Headache. As a result of impact on the central nervous system, caffeine can cause  receptors in the brain to become overloaded, leading to, headaches or migraine.

Other long term effects of caffeine overdose:

  • Insomnia is one of the most common signs of caffeine overdose. Adenosine concentration increases during prolonged wakefulness and decreases during sleep. Caffeine blocks adenosine, getting to  the brain, causing sleep disturbance and insomnia.
  • Caffeine can increase heart rate and  adrenaline level in the body. People who are hypersensitive to caffeine can experience irritability and anxiety as a result of even small doses of the stimulant.
  • Hallucinations is one of the rare signs of too much caffeine.. Caffeine overdose amount leads to adrenaline level soar as the body is under stress as a result of exposure to caffeine.

Death by caffeine? It may come as a surprise, but caffeine overdose can be fatal.Death can occur after  abuse of caffeine pills or energy drinks. Lethal dose of caffeine is 200 milligrams per kilogram of weight (which is equivalent to 25 cups of coffee). High concentration of caffeine in most cases leads to caffeine intoxication , and the consequences are grim.

5 facts  you should know about caffeine before it’s too late

Caffeine has a diuretic effect. Being a diuretic, it has a corresponding effect on the body. Therefore, it is desirable for people with urinary incontinence to cut down on caffeine under the instruction of doctors.

Caffeine speeds up the heart rate. Caffeine doesn’t cause or develop heart disease, but can lead to increased heart rate and arrhythmia.

Caffeine increases blood pressure. After intake, some caffeine sensitive people may experience temporary increase of blood pressure, comparable to exercise stresses. The pressure increase caused by caffeine usually lasts for several hours. If you experience such side effect, contact your doctor with questions about caffeine consumption: maybe you should switch to decaf coffee or limit daily caffeine intake to very small doses.

Caffeine increases cholesterol level in blood. There is no scientific proof that caffeine changes cholesterol in blood. However, unfiltered coffee (brewed through a paper filter) increases cholesterol level significantly.

Pregnancy and breastfeeding. Moderate consumption of caffeine has no adverse effects on pregnancy or childbirth. However, pregnant women have to reduce daily caffeine intake to maximum 1 to 2 cups, and 3 cups per day during breastfeeding. Drinking more than three cups per day can lead to breastfeeding deterioration or / and insomnia.

When normal caffeine intake is too much

Some people are less sensitive to caffeine and can drink several cups of coffee without any consequences, while others feel the symptoms of too much caffeine even after one cup.

Differences in sensitivity to caffeine is determined by many factors:

  • Amount of coffee that you drink
  • Consumption frequency
  • Weight
  • Physical condition (including pregnancy).

Avoid caffeine (even recommended caffeine intake) if you:

  • are scared, feel nervous, have tremor, irritability.
  • have anxiety or panic attacks.
  • have sleep problems
  • suffer from headaches, migraines
  • have heartburn and peptic ulcers. Besides caffeine, there are other substances contained in coffee and tea which stimulate digestive acids and can cause heartburn. Even decaffeinated coffee (decaf drink) can cause stomach upset.
  • prone to depression or you are take antidepressants: caffeine may reduce its effectiveness.
  • If you are allergic to caffeine-containing products

Caffeine and children. Children are sensitive to caffeine in the same way as adults, with caffeine excreted from their bodies two times faster. Scientific researches show no evidence that caffeine cause hyperactivity in children or develop attention deficit disorder.


To avoid side effects of too much caffeine, always control the consumption of it. Talk to your doctor or dietitian if you are experiencing any of these symptoms and / or suspect that caffeine aggravates them. If you feel that everything is OK, don’t exceed healthy caffeine intake.

We hope that negative signs and undesirable symptoms mentioned in the article won’t make themselves felt in your case.