Why does coffee make me tired?

In this brief blog, we will address the query,” Why does coffee make me tired?” We will discuss the various ways that caffeine affects the body and causes tiredness. We will also look at some ways that can assist in minimizing these effects.

Why does coffee make me tired?

Coffee usually affects the body in certain ways that can result in feeling tired or sleepiness. Let us take a look at some reasons why this happens.

Coffee blocks adenosine

Adenosine is a molecule found in the central nervous system and it also aids in digestion. It helps in the regulation of the sleep-wake cycle. During the day when you are awake, the adenosine levels are usually more and this eventually makes you sleepy and drowsy by lowering the activity of the cells in the basal forebrain. When you sleep, the adenosine levels usually go down.

Intake of caffeine in the system usually blocks the brain’s adenosine receptors from receiving adenosine although it does not halt the production of adenosine or the ability of the creation of more adenosine receptors.

This therefore means that when the effects of the caffeine in the system wear off then there will be a lot of adenosine seeking to bind to its receptors and as such this results in tiredness.

Coffee is a diuretic

Caffeine is a well known diuretic. A diuretic is a substance that aids the body in getting rid of excess water through the urine. This therefore means that drinking a lot of water can increase the risk of dehydration through frequent urination.

Although a lot of researchers claim that drinking beverages that contain caffeine does not have an impact on the urinary output in the long term similarly to any other beverage.

However, if you notice that when you drink coffee, it results in frequent urination which is not the norm,then you might end up feeling more tired more often.

This is because when you urinate, the body loses water and this water loss lowers the amount of fluid in the blood. This can further affect the functioning of the cardiovascular system to how it responds to maintain both blood pressure and flow.

Loss of a lot of fluid in the body (dehydration) can result in a rapid heart rate and also low blood pressure. This can cause you to feel tired and even result in sluggishness.

When the body cells are dehydrated they usually lose the volume of fluid and this not only affects their day to day functioning it also makes you feel sluggish. 

Caffeine is also known to cause vasoconstriction which is the narrowing of the blood vessels. This can affect the flowing of the blood to the different body parts.

The sugar in your coffee

If you usually add sugar to your coffee, you may experience a drop in energy levels after drinking coffee. The sugar added in the coffee can be in various  forms such as whipped cream or shots of syrup. 

The body breaks down sugar more quickly as compared to caffeine and therefore after the sugar is utilized by the body you can experience that your energy levels are low. This can happen at different rates depending on the person.

How do you minimize these effects?

You can follow the below guidelines so as to minimize the effects the caffeine;

  • Limit your intake to upto 400 mg of caffeine in a day, this is equivalent to 2-4 8 ounce cups of brewed coffee in a day.
  • Steer clear or cut down on coffee based drinks which contain sugar syrups and creams. Also limit the use of any added sweeteners.
  • If you usually get an afternoon slump try decaf coffee or tea after your lunch meal.

You should also be aware that it is not only coffee that has caffeine beverages such as soft drinks, energy boosters and even pain relievers also contain caffeine. The effect of caffeine in the body is dependent on the overall amount contained in your system.


In this brief blog, we have addressed the query,” Why does coffee make me tired?” We have discussed the various ways that the body affects the body and causes tiredness. We have also looked at some ways that can assist in minimizing these effects.



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