The Caffeine Crash: Why Does Coffee Make Me Sleepy

If you’ve ever had coffee and felt tired afterward, you may be wondering why coffee causes drowsiness — read all about the causes of caffeine hunger in our article.

We at Bright Side were surprised to find out that coffee can help you sleep better. And we’ve searched the Internet to find out the reasons behind it.

1. Caffeine doesn’t disrupt your sleep.

There’s a popular belief that having coffee late in the day can interrupt your sleep. However, we have good news for all coffee lovers: a late-night cup of coffee won’t affect your sleep. A group of researchers came to the conclusion that drinking coffee within 4 hours of bedtime does not disturb your sleep. They monitored 785 volunteers for about a week using wrist sensors and sleep diaries, and the results were surprising: caffeine did not affect their sleep.

2. You might wake up feeling more energized.

Having a cup of coffee before taking a nap may actually boost your energy levels instead of making you tired. To help you feel sleepy, your body produces adenosine — a chemical that promotes sleep. Caffeine prevents adenosine from being received by your brain.

3. Coffee can make you feel tired.

Have you ever felt like you need to go to the bathroom after drinking coffee? This happens because caffeine serves as a diuretic. In other words, coffee makes you more likely to take frequent trips to the bathroom. When caffeine makes your body lose fluids, dehydration takes effect, which, in turn, can make you feel tired and sleepy. To reduce the sleepy effect and prevent your body from getting tired, you have to supplement the dehydration by drinking water.

4. It lowers your blood glucose levels.

Another way coffee can make you sleepy and tired is by influencing the glucose level in your blood. If you like your coffee sweet with lots of sugar and whipped cream, you may experience a sugar crash soon after drinking it. When your body ingests processed sugars, your blood glucose levels begin to drop. As a result, you may feel tired due to a lack of energy.

5. Mold in coffee may cause fatigue.

As gross as it may sound, when you’re drinking your cup of coffee, you are likely having a pretty moldy drink. Studies have shown that most coffee beans are contaminated with mold. Hence, your fragrant cup of coffee is full of toxins contained in the mold that can make you feel, drowsy, sleepy, and tired in general.

6. Your body might translate stress into sleepiness.

Have you ever noticed that your cup of coffee can give you the jitters? That’s because drinking coffee doubles the levels of stress hormones in your body, even if you consume the same amount of caffeine every day. And after the initial response to stress has passed, you may want to sleep to process the experience, as sleepiness and fatigue are natural reactions your body has to stress.

Do you drink coffee before going to bed? Have you noticed how it affects your sleep?