Millions of people around the world begin their day each morning with a cup of coffee—or five. In fact, more than three-quarters of Americans drink coffee daily, according to the National Coffee Association. Recent studies show that approximately 52% of American adults consume 70 gallons of coffee over the course of a year, and the average American is spending over $1,000 each year on coffee alone.
Even though coffee has proven to have many health benefits, such as preventing heart disease, diabetes, and Parkinson’s, there are also many risks that come with excessive caffeine consumption. The average cup of coffee contains about 200 milligrams of caffeine, but if you buy your coffee from Starbucks, the number could be much higher, with over 400 mg of caffeine in a single venti-sized (20 ounce) cup.
While a few cups of coffee per day are perfectly safe, once your caffeine consumption gets nearer to 500 or 600 milligrams, you may start experiencing some of the early signs of caffeine intoxication. If you consume high amounts of caffeine every day, either through coffee, energy drinks, or caffeine pills, your body can form a caffeine addiction. And just like any addiction-forming drug, you have the potential for overdose as well. Here are a few things that you could experience with a caffeine overdose:
- Increased heartbeat: Since caffeine is a stimulant for the central nervous system, it will naturally increase your heart beat as soon as 15 minutes after ingesting.
- Heart palpitations: After consuming higher amounts of caffeine, your heart will also start to flutter and palpitate.
- Increased blood pressure: High amounts of caffeine cause your adrenal glands to release more adrenaline, which will in turn cause your blood pressure to increase.
- Cardiac arrest: The increased blood pressure from high caffeine intake along with the effects of the stimulant on your cardiovascular system can lead to dangerous consequences including cardiac arrest and even death.
- Acid reflux: Caffeine relaxes the esophagus, which can contribute to gastroesophageal reflux, which can cause heartburn to occur or make it worse.
- Diuresis: Higher doses of caffeine will increase the blood flow through the kidneys and dilate the blood vessels, which will cause the kidneys to produce more waste. This means that you will experience an increased need to urinate.
- Gastrointestinal problems: Caffeine can also act as a laxative by increasing contractions in the small and large intestinal muscles. This can trigger stomach cramps because predigested food is moving into the intestines prematurely.
- Stomach ulcers: Since caffeine speeds up the gastric emptying process, this can result in highly acidic stomach contents passing into the small intestines, which can lead to the presence of ulcers.
- Restlessness: Since caffeine stimulates hormones such as adrenaline, this can cause your body to have tremors and feel jittery.
- Anxiety: Higher doses of caffeine can create an overall sense of anxiety because of the combination of increased heart rate, increased adrenaline, and heightened senses.
- Rambling thoughts and speech: Speech and thought can be sped up in response to the stimulant effect of caffeine. To a certain point, this can be useful for concentration. However, too much caffeine intake can cause confusion and stuttering.
- Insomnia: One of the reasons caffeine can make you feel suddenly awake is because it inhibits the activity of the neurotransmitter adenosine, which is one of your brain’s natural tranquilizers. When your levels of adenosine are disturbed by frequent, high doses of caffeine, it can inhibit your ability to fall asleep at night.
- Hallucinations: Once your body begins to recognize an overdose of caffeine, it becomes very stressed, which will increase your adrenaline levels even more. This can cause hallucinations.
- Muscle spasms: Prolonged, high volumes of caffeine in the body can cause your muscles to move erratically and cramp up.
- Dehydration: Since caffeine can cause persistent urination and diarrhea, this can upset the body’s fluid balance. Loss of water, vitamins, and minerals needed in order to function properly can cause symptoms of dehydration.
- Headaches: When the sensors in the brain become overloaded by too much caffeine, this can cause intense headaches.