Why Coffee Makes You Sleepy

Why Coffee Makes You SleepyIt’s one of the nation’s favorite pick me up drinks, but with the presence of caffeine you might sometimes be left wondering why coffee makes you sleepy.  It’s unlikely the effect you are going for and can be frustrating if you have a long day ahead, so in this article we will be exploring why coffee causes tiredness, and what you can do to prevent it.

Can Caffeine Make you Tired?

Considering most people drink coffee to help them wake up and get moving, it can be frustrating if you are left feeling tired. Of course the caffeine acts to make you feel more energetic, but it’s the combination of various effects that means that coffee causes sleepiness in some circumstances. It’s often the presence of too much caffeine in your body that will result in tiredness, so it is important that you don’t drink too much.

Your Adrenal Glands

Caffeine itself isn’t enough to make you feel alert when it’s in your body. It is, in fact, the way that caffeine affects the processes of your adrenal glands that result in this. In particular, heightened levels of caffeine will trigger a release of adrenaline, which is the hormone your body uses to prepare itself for unpredictable or dangerous situations.

Adrenaline increases your rate of breathing, will cause your pupils to dilate, increase your heart rate and, as a result, significantly increase the amount of blood that is passing around your body to all of your cells, muscles, and organs.

If you ingest too much caffeine, however, the results can be the complete opposite. This is because your glands will be producing so much adrenaline that they become exhausted. They will stop producing any further adrenaline, even the small amounts that are regularly produced while you are awake to maintain concentration, and this will result in you feeling tired and sleepy.


Another factor that may leave you wondering ‘why do I feel sleepy after drinking coffee?’ is the interactional effects it has on insulin in your body. Essentially the presence of large levels of caffeine in your body will reduce the sensitivity of your insulin production, and this can cause problems.

As you probably know, the body produces insulin as a way to control the levels of sugar. If you have too much sugar in your system you will be full of energy, and if there’s not enough you will end up feeling tired and lethargic. The caffeine limits your body’s ability to respond to the sugar levels as quickly, so you may end up in a situation where there is too much insulin being produced, and you end up feeling exhausted.

Your Sleep Cycle

If you are using coffee to keep yourself awake, you could easily find yourself in a position where you are affecting your sleep cycle. If this happens a lot, then it won’t matter how much coffee you drink, you’ll always end up feeling tired. The reason for this is that you need a regular amount of sleep each day to function properly.

In an ideal world you will be getting 8 hours of sleep per night at the same time each day so your body can adjust to a regular routine, but in practice this is not always possible in the world we live.

Shift patterns, or simply staying up to watch your favorite TV show can affect this and interrupt your sleeping patterns. If you drink coffee late at night to help you stay up, this effect can become more pronounced. For sure it’ll work for a few days, but eventually your body will resist the effects of the caffeine and you can even end up feeling more tired.

How Much Coffee is Safe to Drink?

With all this being said, it doesn’t mean that coffee is bad for you. If you are careful with the amount you drink, then it can actually help you improve your concentration. Too much, as we have said, will result in you feeling sleepy.

So how much is a reasonable amount? This will, of course, depend on your physique, but the general daily guidance for an adult is about 400 milligrams of caffeine. This is the equivalent of four cups of coffee.

Children shouldn’t be drinking caffeine at all, and young adults should do their best to avoid it. By consuming more than this you risk experiencing side effects that can include extreme sleepiness, insomnia, and a variety of other ailments.

The Final Word

Coffee is such a popular drink because of the wonderful flavors, but also because it’s an effective way to wake yourself up. This happens because of the caffeine, which in small doses is perfectly safe to drink. Too much caffeine can, however, be the reason why coffee makes you sleepy because it starts interacting with your body’s’ processes in a negative way.

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