I started drinking coffee 15 years ago, when I was a student. Like many students my sleep schedule was messed-up: I was working late, and getting up late. I loved working at night: it’s quiet, there’s almost no distraction. To compensate for my lack of sleep during the day I drank coffee, sodas, and occasionally tea. After graduating, I stopped drinking coffee and soda for a while. I switched to tea, 2 to 4 cups of tea every weekday for 10 years.

I started drinking coffee again 2 years ago when I started my new job. I drank between 1 to 3 cups of coffee at the start of the day, and 2 to 4 cans of Diet Soda during the day on top of that. I ingested 150mg to 400mg of caffeine everyday. I though that coffee was by far the biggest source of caffeine, but it turns out that sodas, and tea also contain a significant amount. A cup of coffee contains around 100mg, a can of Diet Pepsi has 35mg, while a cup of tea is around 40mg.

How much caffeine is too much? According to Wikipedia, 100mg per day is enough to get you addicted:

[…] people who take in a minimum of 100 mg of caffeine per day (about the amount in one cup of coffee) can acquire a physical dependence that would trigger withdrawal symptoms that include headaches, muscle pain and stiffness, lethargy, nausea, vomiting, depressed mood, and marked irritability.

The mayo clinic recommends cutting back for those who get more than 500mg everyday, I suspect this limit is lower for me.

I had my last coffee Sunday morning, almost 4 days ago. I’ve experience most of the withdrawal symptoms, it’s getting better, but I think I have another day or two before I can feel normal again. I didn’t even consume that much caffeine. It must be awful to be nauseous or vomit on top of the other symptoms. I imagine only big consumers get these problems, but this tells you a lot about how strong the addiction can be. The headaches are especially annoying, they’re caused by an increase of blood flow in the head, compressing the brain. I usually exercise when I want to get my mind off something or try to get back into a healthy routine, but In the case of caffeine withdrawal, exercise seems to make the headaches even worse. Aspirin works well, but it still hurts quite a bit. The worse part is how irritable I am right now, I tend to go crazy when I’m on my own, and idle. I get restless and my mind wanders, thinking of past personal injustices, and how I’ll get revenge: I get angry for noting. I can’t even focus on a book for more than 10 minutes without my mind wandering.

The good news is: it’s almost over.

[…] withdrawals occurred within 12 to 24 hours after stopping caffeine intake and could last as long as nine days.

There were positive side effect: I used to go pee 3 to 5 times a day, not anymore. My sleep seems to improve. Sleep is why I stopped caffeine consumption. I don’t sleep well most nights, waking up tired but not sleepy.

Like most things, caffeine isn’t bad, but it has to be consumed in moderation. I don’t plan to ban caffeine from my life, but I do need to reduce my consumption, and take a break from time to time.