Caffeine: How Does Caffeine Affect The Body



Caffeine is a mellow stimulant found in over 60 plants, including tea leaves, kola nuts, and coffee beans.

Many people drink a beverage with caffeine to feel more energized, such as coffee, tea, soda, or an energy drink.

coffee. Coffee beans, Caffeine

Caffeine is also available in concentrated powder and liquid forms. Cocoa beans and yerba mate contain caffeine as well.

Odorless and somewhat bitter, it is considered the most widely used mind-altering chemical worldwide.

Caffeine is also present in a dietary supplement and an ingredient in several over-the-counter and prescription medications.

It is added to many food products as well. The amount of caffeine per serving is not required to be available on food labels, so you could be taking more caffeine than you know.


Caffeine can increase mental alertness, improve short-term memory, temporarily relieve fatigue, and create a well-being feeling.

When you take it, you often feel less sleepy. Your reaction time increases, you can concentrate better, and your ability to do physical work improves.

However, these effects are temporary, and consuming caffeine does not replace your need to rest.

Caffeine can also affect the body by increasing:

  • your heart rate
  • your blood pressure (temporarily)
  • the amount you urinate (primarily when large amounts of caffeine are consumed)
  • stomach acid secretions

Not all of us respond to caffeine in the same fashion. Some people are more sensitive to caffeine and its effects than others.

The caffeine results can be sensed in as little as 15 minutes and last up to several hours. The length of time caffeine lingers in your body also varies.

Caffeine stays in the bodies of pregnant women and people with liver damage longer than it does with others.

Sensitivity to caffeine differs from one person to another due to age, weight, body differences, medications, and how much caffeine they regularly consume.

In case you take too much caffeine, you can feel restless and suffer from insomnia, and your heartbeat can become irregular.


Due to its capacity to increase alertness and fight fatigue, caffeine is sold as a dietary supplement. It is as well included as an ingredient in some antihistamines.

These medicines can make you sleepy. Including caffeine as an ingredient offsets this effect.

Caffeine is also an ingredient in pain relievers like Excedrin, a medicine for headache relief and migraine drugs. Caffeine improves the ability of these products to address pain.

If you are highly sensitive to caffeine, you should know how much caffeine is included in many supplements and medications you take.

Another prescription drug containing caffeine is called citrated caffeine. It is used to improve breathing problems in infants who are premature.


(FDA), U.S. Food and Drug Administration says caffeine is considered safe to consume in moderate amounts.

For adults, this is about 300 to 400 milligrams per day, the equivalent of three to four cups of coffee. This figure varies from person to person, however.

Caffeine is safe for pregnant women to consume, though the recommended amount is no more than 200 milligrams per day.

Children should consume little to no caffeine, and adolescents should be educated on managing their caffeine intake as they begin to consume caffeine.

For people of all ages, accidentally overdosing on caffeine dietary supplements can lead to severe consequences, including death.

Therefore, such accessories should be kept out of the reach of children. If a child accidentally ingests caffeine pills, medical care should be sought immediately.

If you consume 500 to 1,000 milligrams of caffeine per day, depending on your tolerance, you can develop caffeinism.

This condition causes symptoms such as:

  • restlessness
  • irritability
  • nervousness
  • anxiety
  • muscle twitches
  • headaches
  • inability to sleep
  • racing heart

If you heavily overuse caffeine for the long term, you can develop disorders including caffeine intoxication, caffeine-induced anxiety disorder, caffeine-induced sleep disorder, and non-specific caffeine-induced disorder.

These conditions have serious consequences for your physical and mental health and require medical intervention.

For example, caffeine intoxication can cause the rhythm of the heart’s ventricles to become irregular, which can lead to death.

The concentrated powder and liquid forms of caffeine contain about 3000 milligrams of caffeine per teaspoon.

Because of the amount of caffeine in these products and their wide availability on the internet, the FDA has warned them about them.

It is accessible to abuse caffeine through such concentrated powder and liquids.


Regular consumption of moderate amounts of caffeine may come with benefits.

Studies have shown that consuming this amount of caffeine daily can:

  • improve memory, brain function, and reaction time
  • decrease depression
  • improve athletic performance
  • extend life expectancy
  • reduce the risk of diabetes
  • lower the risk of some forms of cancer
  • delay the onset of Alzheimer’s disease
  • delay the onset of Parkinson’s disease

Breastfeeding women pass any caffeine they consume to their children through their breastmilk.

Though this caffeine may have the expected impact on the breastfeeding woman, it can affect the child who is breastfeeding differently.

These infants may be restless or irritable and unable to sleep well.

When you regularly consume caffeine, you can become physically dependent on it and tolerate its effects.

This can result in the need for more caffeine overtime to maintain the same stimulating effects.


If you regularly consume caffeine and suddenly stop, you can experience withdrawal symptoms within as little as 12 hours from the last time you had caffeine.

These symptoms may include:

  • Headache
  • Fatigue
  • Sleepiness
  • Irritability
  • Nausea
  • Lack of ability to concentrate
  • Mild depression

Withdrawal symptoms last for up to five days and often are the worst at 48 hours after the last time you had caffeine.

If you gradually cut down the amount of caffeine you consume daily by about 50 milligrams, these withdrawal symptoms are much less intense, if they occur at all.


“Caffeine.” Johns Hopkins All Children’s Hospital. (accessed September 6, 2019).

“Caffeine.” Psychology Today. March 14, 2019. (accessed September 6, 2019).

“Caffeine: How much is too much?” Mayo Clinic. March 8, 2017. (accessed September 6, 2019).

“Caffeine (Oral).” November 2, 2018. (accessed September 6, 2019).