8 Side Effects Of Too Much Caffeine: How Much Is Too Much?

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Coffee is a popular drink. If you live in a city, you won’t have to look far to find a coffee shop. But are there any side effects of coffee? If you consume coffee at moderate dosages, you will not see any caffeine side effects on the body.  The problem starts to appear as you increase the dosage. 

What is the worst side effect of coffee? If an individual weighing 150 pounds consumes 300 milligrams of caffeine a day, they can develop hyperactive bladders. If that happens, they will have to make frequent visits to the bathroom. But for that to happen, the caffeine dosage needs to be excessively high.

Don’t start to panic. All the side effects listed below will only trigger if you consume crazy amounts of caffeine a day. You aren’t crazy, are you?

Does Coffee Have Any Side Effects On the Human Body?

Did you know coffee is used as a treatment for Cancer? As part of the Gerson therapy1, cancer patients are given caffeine as a form of an enema. They are placed on a diet that includes livers, vegetables, and other supplements. But, this kind of cancer treatment is strictly prohibited in the USA.

This brings us back to whether coffee has any benefits for the human body and coffee’s side effects. According to a statistic by the US Food and Drug Administration (FDA), 80% of all American citizens consume coffee each day.   With so many people drinking coffee every day, the right question is about the side effects of excessive coffee consumption.

8 Side Effects of Coffee on the Human Body

For a healthy adult, 400 milligrams of coffee a day is the benchmark. If you stick to this benchmark, your body will soon grow a tolerance for caffeine. The most apparent effect of coffee is it boosts your alertness. Furthermore, according to a study, regular consumption of coffee reduced suicidal tendencies by 45 percent. 

But we aren’t here to learn about the benefits of coffee. Let us dive right into the side effects of coffee. 


Side Effects

Some people say that a cigarette in the morning helps with bowel movements. And for some, it is coffee. The effects of Caffeine on the body include its laxative features. It triggers the release of gastrin from the stomach, which facilitates bowel movement.  

Both Decaf and regular coffee has this benefit. However, excessive coffee consumption can lead to diarrhea and loose tool. This is because caffeine itself increases bowel movement by facilitating contractions in the digestive tract.


Side Effects

Caffeine travels to the human brain and connects with Adenosine receptors. This way coffee tricks your brain into thinking you are not tired. Thus you can keep on working for long hours and kill the drowsiness after a long meeting. At the same time, it triggers the release of adrenaline in your body, which gives your body an energy boost. 

But if you take excessive amounts of coffee each day, these chemical substances might have a more substantial effect on the body. Once you reach that state, you will feel more anxious.

According to the American Psychiatric Association, Caffeine-Induced-anxiety is caused by excessive consumption of coffee. 


Side Effects

The next side effect of caffeine is sleep deprivation. You might not think twice before making yourself a cup of coffee after you wake up in the morning, or even later in the evening after you come back from work. 

But coffee can make you develop insomnia. In the elderly, it also reduces sleeping time significantly. Caffeine can also make adults take longer times to fall asleep, and worse, completely ruin their normal sleep cycle.

Muscle Atrophy

Rhabdomyolysis is a dangerous health condition that breaks down the human muscle. The dead muscles then enter the bloodstream and result in kidney failures and other serious issues. Rhabdomyolysis is a direct result of snake bites, drug abuse, trauma, and muscle strain. But excessive caffeine in the body can also trigger this health condition. 

If you are used to drinking 2-3 cups of coffee each day and never had any harmful side effects, you don’t need to worry that much. But if you are new and aren’t accustomed to drinking coffee, you should limit your daily caffeine intake to 250 milligrams a day. 


Side Effects

There is no doubt that caffeine gives an energy boost to the body, and it stimulates the brain. But the effect of caffeine starts to fade away after roughly 6 hours. When that happens, the body experiences a rebound of fatigue. 

This rebound effect can make people feel more tired and exhausted. However, you might not feel its impact if you make yourself another coffee right before the rebound kicks in.

High blood Pressure

Side Effects

Caffeine stimulates the human nervous system, thus manipulating the average blood pressure in the human body. As high blood pressure runs the risk of permanently damaging the arteries’ muscles, it can lead to heart attack and stroke.

If you already have high blood pressure, you should avoid drinking coffee.  


Side Effects

You might not think that caffeine can grow into an addiction for you. And compared to other hard-core drugs, you are right. Caffeine won’t get you hooked.

However, with time, people might start to grow a dependency on coffee. Once they reach that stage, they will find it hard to focus on the task at hand without drinking a cup of coffee first. Also, caffeine triggers some brain chemicals that are usually triggered by amphetamines and cocaine. 

Increased Heart Rate

Side Effects

Soon after you drink a cup of coffee, you will realize your heart has started to beat faster. The worst thing that can happen to you is atrial fibrillation. Under this condition, your heart starts to beat in alternate rhythms.

However, this is very rare. Unless you consume excessively high caffeine or highly-concentrated caffeine energy drinks, you are not much likely to experience atrial fibrillation.


Now that we know the side effects of coffee, it is important to understand that different people respond differently to caffeine. And it all boils down to their gene. 

However, if you stick to a moderate coffee dosage per day, you won’t develop any severe side effects of caffeine on the body. As mentioned earlier, 400 milligrams of coffee a day is the benchmark for healthy individuals.