Most people can eat and drink caffeine and still be healthy. But too much could be bad for your health. The following rules show how much caffeine is too much: A day’s worth of caffeine for an adult shouldn’t be more than 400 milligrams (mg), which is about four to five cups of coffee.1 Children and teens shouldn’t have more than 2.5 mg of caffeine per kilogram (kg) of body weight.
One study found that about 85% of people in the U.S. drink at least one caffeinated drink every day, with an average of 165 milligrams of caffeine being taken each day.
Even though low to average amounts of caffeine are usually safe, high amounts can cause unpleasant and even dangerous side effects.
Both coffee and tea are very healthy drinks.
Most of them have caffeine, which may improve your mood, digestion, and mental and physical performance.
Here are 10 negative results of taking too much caffeine.
When you take in more coffee than is good for you, it can cause side effects. Some signs that you’ve had too much coffee are:
- Headache
- Anxiety
- Trouble sleeping
- Irritability
- A faster heart rate
- Need to drink more
- Frequent urination
- Chest pain
- Trouble digesting food
- Breakdown of Muscle
1. Anxiety
Caffeine is known to make people more awake.
It works by stopping a chemical in the brain called adenosine from making you feel tired. At the same time, it makes adrenaline, the “fight-or-flight” hormone that gives you more energy, come out.
But if you take more of it, these effects may be stronger and make you anxious or nervous.
In fact, the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) lists four syndromes that are linked to caffeine. Caffeine-induced anxiety disorder is one of these syndromes.
Most people get nervous, jittery, and other similar feelings when they take in 1,000 mg or more of caffeine per day or more. However, people who are sensitive to caffeine may feel the same way even with a low amount of caffeine.
When taken all at once, even small amounts have been shown to speed up breathing and make people feel more stressed.
In a study with 25 healthy men, those who took about 300 mg of caffeine had more than twice as much stress as those who took a fake drug.
Cortisol levels were the same for both regular and occasional caffeine drinkers, which suggests that the chemical may have the same effect on stress levels no matter how often you drink it.
Still, these are only early findings.
There are many different amounts of caffeine in coffee. For reference, a large (“grande”) coffee at Starbucks has about 330 mg of caffeine.
If you often feel worried or jittery, you might want to look at how much caffeine you’re drinking and cut back.
2. Trouble While Sleeping
In moderate and high amounts, caffeine may cause mild sleep problems when taken close to bedtime. Caffeine before bed can lower the amount and quality of sleep and make it harder to fall and stay asleep. It is best to not have coffee up to six hours before bed.
But if you drink coffee often, its effects won’t be as bad for your sleep over time. Your body can get used to the effects of caffeine and build up a tolerance over time.
3. Headache ( Pain In The Head)
Caffeine is often used as a psychostimulant, which means it is a drug that speeds up the central nervous system. This is why a lot of people drink coffee or tea with caffeine in the morning to wake them up. Caffeine is sometimes used to relieve pain, like in the pain medicine Excedrin, which has aspirin, paracetamol, and caffeine in it. But headaches can be caused by both getting too much caffeine and stopping caffeine.
Caffeine can cause something called “caffeine rebound.” This means that if you drink a lot of caffeine, you may feel like you need to stop after the original effects wear off. In general, the National Headache Foundation says that a small amount of coffee is fine. However, if you get headaches often, it’s best not to use it every day.
4. Irritability
People who drink a lot of caffeine are more likely to feel irritable, but this has mostly been seen in people who drink a lot of caffeine. But if you already have a mental or anxiety problem, you may feel irritable even if you drink less caffeine than the average person.
Even though more study needs to be done to find out exactly how much caffeine makes people irritable, you may want to cut back if caffeine makes you angry or irritable.
5. A Faster Heart rate
In one case study, a woman who tried to kill herself by taking a large amount of caffeine powder and pills ended up with a very fast heart rate, kidney failure, and other major health problems.
This result doesn’t seem to happen to everyone, though. Some people with heart problems may even be able to take in a lot of coffee without getting sick.
In one controlled study, 51 people with heart failure who took 100 mg of coffee every hour for five hours had normal heart rates and rhythms.
Even though study results were mixed, you might want to cut back on caffeinated drinks if you notice changes in your heart rate or beat after drinking them.
6. Need To Drink More Water
Researchers have found that even small amounts of coffee can make some people feel thirstier. Even after just one cup of coffee, caffeine drinkers felt thirsty the most. People who drink coffee every day couldn’t feel thirst at this level.
There is no proof that drinking a lot of coffee makes you thirsty. But it’s possible that the reason you’re thirsty is because you’ve had too much coffee.
7. Frequent urination (High BP)
Caffeine makes you pee. This is something that makes you need to go to the toilet because it makes you pee more. Caffeine can make more blood flow to the kidneys, which makes them less able to re-absorb salt and water as they filter the blood. This makes the bladder fill up with more pee.18 People with a bladder that is too busy may be more likely to pee more when they drink caffeine.
When you pee, you also lose important nutrients. One study found that drinking about four cups of coffee lowered levels of thiamin, B12, calcium, magnesium, sodium, phosphate, chloride, and potassium. This could be bad for the health of your bones.
Even though no one knows for sure how more caffeine affects the bladder, having to go to the toilet often could be a sign of too much caffeine or something else.
8. Pain In the Chest
When the heart isn’t getting enough blood, it hurts. As the amount of coffee goes up, so does the amount of blood flow restriction. So, too much coffee can make your chest hurt. But it usually takes a lot of caffeine to cause chest pain, so overall the risk is low if you only drink one to three cups of coffee a day.
People who have health problems, take medicines, or are sensitive to caffeine may feel less blood flow and chest pains after less than two cups of coffee. If you get chest pains after drinking caffeine, it could be a sign of something dangerous. Get help from a doctor right away.
9. Trouble Digesting Food
Many people find that drinking a cup of coffee in the morning helps them go to the toilet.
Gastrin, a hormone made by the stomach that speeds up activity in the gut, is thought to be the cause of coffee’s laxative effect. Also, it has been shown that decaffeinated coffee has the same effect.
Because of this, it’s not strange that some people who drink a lot of caffeine may end up with loose stools or even diarrhea.
For a long time, people thought that coffee caused stomach ulcers. However, a big study of more than 8,000 people found no link between the two.
On the other hand, some studies show that caffeinated drinks may make some people’s gastric reflux disease (GERD) worse. This seems to be true of coffee more than anything else.
In a small study, when five healthy adults drank caffeinated water, the muscle that stops stomach contents from going up into the throat (which is a sign of GERD) became less tight.
Since coffee can have big effects on how your digestive system works, you might want to drink less of it or switch to tea if you have problems.
10. Breakdown of Muscle
Rhabdomyolysis is a very dangerous condition in which damaged muscle fibers get into the bloodstream and cause kidney failure and other problems.
Rhabdomyolysis is often caused by injury, infection, drug abuse, muscle strain, or bites from snakes or insects that are deadly.
There have also been a few cases of rhabdomyolysis linked to too much caffeine, although this isn’t very common.
In one case, a woman who drank 32 ounces (1 liter) of coffee with about 565 mg of caffeine felt sick, threw up, and had dark pee. After being given medicine and water, luckily, she got better.
Importantly, this is a lot of caffeine to take in quickly, especially for someone who isn’t used to it or who feels its effects very strongly.
If you want to lower your risk of rhabdomyolysis, you should limit your caffeine usage to about 400 mg per day, unless you’re used to taking in more.
11. Habit ( Addiction)
Coffee has many health benefits, but excessive consumption can become addictive.
According to a comprehensive analysis, despite the fact that coffee stimulates the same brain chemicals as cocaine and amphetamines, it does not cause addiction in the same manner that these drugs do.
However, it has the potential to create physical or mental dependence, especially at higher doses.
Sixteen people participated in a study where they performed a word test after going without coffee for 24 hours. Caffeine addicts are the only ones who have a significant preference for caffeine-related terms and an intense desire for caffeine.
Caffeine consumption frequency appears to be correlated with dependency.
In another study, 213 regular caffeine consumers completed questionnaires after staying caffeine-free for 16 hours. Regular users were more likely to have worsening withdrawal symptoms such as headaches and fatigue compared to occasional users.
The molecule doesn’t appear to induce real addiction, but there’s a significant possibility you’ll develop hooked on the benefits of coffee or other caffeinated drinks if you drink them frequently.
Important Note
Many people seem to get a lot of health benefits from light to moderate caffeine use.
On the other hand, very high doses may cause side effects that make it hard to go about daily life and may even lead to major health problems.
Even though each person reacts differently, the benefits of high intake show that more isn’t always better.
To get the benefits of caffeine without the bad side effects, take an honest look at how you sleep, how much energy you have, and any other things that might be affected. If you need to, cut back on your caffeine usage.