TL;DR The ideal amount of caffeine intake in a day boils down to 400 mg, which is equivalent to many different things depending on the food or drink you're taking. When you consume more than this amount, some adverse effects may take place like headache, anxiety, and insomnia.
Coffee, tea or (caffeine) mints.
So, which of these have you popped or downed today?
These products all contain varying amounts of caffeine, alongside others you wouldn't have thought to contain it. Ice cream, frozen yogurt, breakfast cereals, pudding, pain medications … even cocoa butter lotion apparently all have it! 
Do you like most (or all) of these products? Then you must be wondering how much caffeine you take in daily.
We've got you covered.
Keep reading to find out the safe amount to consume and what might happen if you get too caffeine-happy.
Let's start with a very important question:
How much is too much?
Studies have shown that caffeine remains in the safe zone when consumed in low-to-moderate amounts . But what exactly does “low-to-moderate” mean?
The most important figure to remember on this topic is...
400 milligrams (mg).
That’s the amount of caffeine that’s considered safe to consume in a day… at least for adults. 
If you’re wondering what 400 mg means, you can refer to image below:
Note that caffeine content varies in different products so don’t forget to check the label!
And if you’re wondering how much the “killer” amount is (literally), then USA Today reports it would “likely take anywhere from 50-100 cups of coffee,” or a teaspoon of pure powdered caffeine ingested at once. 
Now you must really love your caffeine to death if you take in that much!
Drinking too much coffee or tea can cause withdrawal symptoms, caffeine rebound and medication rebound, which can all lead to migraine or the worse version of your typical headache. How this happens is covered in our article “Does caffeine cure or cause migraines?”
From modest doses [7, 8] to incredibly high intake (1,000 mg or more) a day [9, 10] caffeine could cause nervousness, rapid breathing, stress and mood swings. And studies say these adverse effects can take place regardless of how many times you have your caffeine – whether you’re a coffee-lover or just an occasional drinker. 
Read this article to find out when’s the best time to drink coffee.
Muscle tremors or rhabdomyolysis
Excessive caffeine intake can also cause rhabdomyolysis, which is a “serious syndrome due to a direct or indirect muscle injury. It results from the death of muscle fibers and release of their contents into the bloodstream.” [14, 15, 16, 17, 18]
One study cited a woman who guzzled a liter of coffee with 565 mg worth of caffeine and eventually suffered from symptoms of rhabdomyolysis, i.e. nausea, vomiting and dark urine. Don’t worry, she recovered after getting medical attention. 
High blood pressure
Rapid heart rate
Stimulant overload can also alter the rhythm of your heartbeat, which was reported among young people who had gone overboard with their energy drinks. 
More trips to the toilet
Most research reports higher likelihood of frequent urination or inability to control urination with excessively high caffeine intake, especially among older people or those suffering from incontinence.
In some cases, high consumption may even likely develop incontinence among those with a healthy bladder. 
While caffeine may be safe for adults, its effects could vary based on people’s tolerance. Research shows that genes may have something to do with it. That’s why some can have more cups of coffee over others without having any drawbacks. [28, 29]
Some people though should carefully watch their intake, especially the following:
The key to consuming caffeine without feeling robbed of your daily fix is to pay attention to your body and whether you're seeing signs of any of the adverse effects above.
If you think you're heading towards the danger zone, try to ease off on your favorite caffeine products and mix them up with decaffeinated ones.
But the most important one is to know is the content of the products you consume. Check the label, but be vigilant at the same time (some products may be disclosing a lower amount than the real one).
If you're not sure how much caffeine a product is supposed to have, fret not. Here's an infographic to guide you the next time you have your caffeine.
Stories of coming back from a downfall after great success are inspiring for anyone—even for young people who haven’t made their mark on the world yet. History and mythology are filled with people who were at the height of success, crashed and came back again.
Sometimes, people need to lose everything material to realize that they didn’t need it, or that the health and safety of their families are worth more than all the success and gold in the world. Sometimes people come back even stronger and more successful than before they “fell.”
Unless you work outdoors or indoors in a job where you are physically active all day, it can be difficult for some people who have desk jobs to stay awake at work without caffeine.
Maybe the most important thing you can do to make sure you don’t nod off at work is to get a good night of sleep, at least 7 to 8 hours, at a regular time every night. Boredom can also cause you to nod off. Other than getting a good night’s sleep and having a fascinating job, there are things you can do to stay awake.
How do investment bankers stay awake on their 18-hour shifts?
Investment bankers work such long hours that many resort to chemical stimuli. There have been rumors of methamphetamine and cocaine use among investment bankers to burn the midnight oil. Other investment bankers take Ritalin or Adderall, which are given to children with ADHD but which are stimulants for adults. But the mainstay is probably coffee, energy drinks, and other concoctions containing caffeine.