6 Side Effects of Having Too Much Caffeine

Side effects of caffeine. (Image via Unsplash/Nathan Dumlao)
Side effects of caffeine (Image via Unsplash/Nathan Dumlao)

Caffeine is a natural chemical found in tea and coffee. It's popularly known as a stimulant agent and is generally used in beverages. The molecule binds to the adenosine A1 receptor and blocks the action of adenosine. That results in the release of acetylcholine, which can make one feel energetic and attentive.

It's known to lift mood, enhance metabolism, and improve physical and mental performance. It's safe to consume caffeine in low to moderate amounts, but anything higher can cause side effects. Overdosing may have even more dangerous side effects. People who do not usually consume coffee often complain more about these side effects.

This stimulant is also often found in its anhydrous and pure form inside various pre-workout powders. It's also added to energy drinks, which are popular nowadays. In this article, we will discuss the commonly observed side effects of having too much caffeine.


Is caffeine bad for you?

Caffeine does not cause harm when taken in normal doses. Coffee addicts can often overdose and suffer from the following side effects:


1) Insomnia

The most common side effects include sleep issues. In insomnia, the amount of time it takes to fall asleep gets prolonged.

Caffeine can remain inside the body for about five to six hours, which makes it unsuitable to drink it in the evening or at night. Energy drinks also contain high doses of this stimulant and must also be avoided.

2) Addiction

Being a stimulant, caffeine is addictive in the same way as cocaine or other drugs. It can trigger certain hormones in our body and make us dependent on them psychologically.

That usually occurs when the stimulant is taken regularly in high doses. Studies have indicated that such addictions can also trigger withdrawal symptoms. This situation can be extremely distressing and cause more harm to the brain than benefits.

3) Increased heart rate

The level of acetylcholine and adrenaline are affected by the presence of caffeine. That occurs due to the blockage of adenosine receptors. These two hormones are crucial for the proper functioning of the heart. Overdosing can lead to irregular or increased heart rate, but that does not occur under normal circumstances.

4) Anxiety

Anxiety can be due to high doses of coffee. (Image via Unsplash/Nik Shuliahin)
Anxiety can be due to high doses of coffee. (Image via Unsplash/Nik Shuliahin)

The hormonal impact of high doses of caffeine also includes anxiety. Caffeine triggers the release of adrenaline, which is a hormone responsible for the 'fight-or-flight' response.

Overdosing on this stimulant has been reported to cause nervousness, jitters, and anxiety. The severity of anxiety increases as more adenosine receptors get blocked. That can also lead to a medical condition characterized by increased resistance to the adenosine A1 receptor, which can be overcome by gradually reducing coffee intake.

5) Digestive issues

Caffeine can trigger the release of gastrin, a hormone that stimulates the emptying of the gut. That can lead to unwarranted contractions in the intestine, leading to an increased frequency of defecation.

Due to this phenomenon, coffee is used by many to relieve the symptoms of constipation and flatulence. However, very high doses of coffee can damage the intestine and even cause certain cancers in the gut.

This chemical can also exacerbate the symptoms of gastroesophageal reflux disease (GERD). Reducing the intake of coffee has been found to be helpful in such situations.

6) High blood pressure

Coffee can impact blood pressure. (Image via Unsplash/Mockup Graphics)
Coffee can impact blood pressure. (Image via Unsplash/Mockup Graphics)

Fluctuations in the levels of acetylcholine or adrenaline can have a huge impact on blood pressure. That's due to the fact that both hormones are responsible for the constriction and relaxation of the blood vessels.

Constrictions in the blood vessels can cause elevated blood pressure. Due to that reason, people suffering from high blood pressure are often asked to avoid coffee completely.


Caffeine is a stimulant present in tea, coffee, and other products, including face creams, skin gels, skin scrubs, facewash gels, and shampoos.

At moderate to low levels, caffeine is relatively safe. However, overdosing can cause various side effects as mentioned above. Beverages containing caffeine can be easily replaced with others for better health.

This chemical is also known for its weight-loss properties and is often used as a pre-workout supplement for men and women. However, people with medical issues related to the kidneys or liver must not take coffee without advice of a registered medical practitioner.

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Edited by Bhargav