If waking up depends on drinking coffee to perk you up, you’re not alone. Four out of five adults consume caffeine daily.

Caffeine consumption depends on the caffeinated products you prefer. A cup of tea has only 14 to 60 milligrams of caffeine, depending on the type, while coffee has up to 200. You also consume caffeine if you enjoy energy drinks, colas, or chocolate products.

While caffeine is usually not dangerous in moderation, consuming too much can hurt your health.

How much caffeine is allowed for people?

Most adults can safely consume about 400 mg of caffeine per day. You get this from drinking four to five medium-sized cups of coffee.

This is usually a safe amount, but people’s tolerance for caffeine varies. Signs that you have consumed too much caffeine include:

  • sleep problem
  • Headache
  • dizziness
  • heart beat
  • dehydration

The more caffeine a food or drink contains, the more likely it is to cause side effects. Most people feel the effects of caffeine up to an hour after consuming it. After four to six hours, your body burns about half of what you put in.

How does caffeine affect your nervous system?

Increased alertness

Caffeine is a stimulant. In the brain, it blocks the effects of a chemical called adenosine, which makes you feel more alert and energetic afterwards, which is why many people drink coffee or tea to stay awake.

Sleep cycle changes

Caffeine may keep you awake even when you don’t want to. Levels of the hormone melatonin, which the body needs to fall asleep, decrease in the presence of caffeine. If you have trouble sleeping, limit your caffeine intake in the afternoon and evening.

feeling anxious

Another downside is that caffeine may make you feel jittery or anxious, especially if you consume too much. If you have an anxiety or panic disorder, your doctor may advise you to avoid caffeine.

Increased dopamine levels

Caffeine can boost your mental well-being. It increases the flow of dopamine, a brain chemical that makes you feel happy and engaged with the world around you. Maybe that’s why drinking moderate amounts of coffee reduced the risk of depression and suicide in some study participants.

Positive effect on memory and cognition

Caffeine may even help you think and remember better. Study participants who drink coffee perform better on tests. Also, older people who consume caffeine may be less likely to develop Alzheimer’s disease and other age-related memory problems.


There is a possibility of caffeine addiction. If you have headaches, feel depressed, or have trouble concentrating when you eliminate your usual intake, or feel like you can’t stop caffeine despite the side effects, it’s best to stop.

How Caffeine Affects Your Heart

For the most part, caffeine is safe for your heart. There is no evidence that it raises blood pressure or causes dangerous heart rhythm disturbances called arrhythmias. Of course, the caffeine in energy drinks affects your heart differently. Energy drinks may be an exception. If you get 32 ​​ounces of caffeine from an energy drink, you may have an abnormal heart rhythm and slightly elevated blood pressure six hours later.

How caffeine affects digestion and urination

You may have heard that some people say that coffee causes heartburn. Caffeine increases the amount of acid your stomach produces. Some scientists attribute this effect to the bitter taste of caffeine, so a more bitter-tasting food or drink creates more acid.

If you have gastroesophageal reflux disease (GERD), you may find that caffeine makes your symptoms worse. Caffeine is also a diuretic, stimulating your body to urinate more.