20 Signs You Might Be Drinking Too Much Coffee

Multiple studies have linked caffeine to mood and emotional problems such as anxiety and depression. Feeling restless, anxious, and/or irritated are not uncommon among people who may have had one or two extra cups of coffee. One study even suggests that people who consumed more than 1,000 milligrams of caffeine in one day showed virtually the same symptoms as people suffering from anxiety disorder.

Being a stimulant, caffeine may temporarily make people feel more alert, which is why most people drink caffeinated beverages such as coffee, tea, sodas, and energy drinks. But caffeine has that effect because it blocks sleep-inducing chemicals in the brain and increases adrenaline production, according to the National Sleep Foundation. Consuming six or more cups a day, which is considered excessive, may prevent some people from falling asleep — and the damage to the body when you do not get enough sleep can be serious.

Stomach aches are usually associated with spoiled food, but in some cases the culprit could be that cup of jo. Some research by European universities suggests that caffeine may stimulate molecular mechanisms that lead to the production of stomach acid in stomach cells, causing stomach aches. The authors of the research say dark-roasted coffees may be a better choice because they contain a compound that reduces acid production.

It is relatively common to try and treat headaches with a strong cup of coffee. Caffeine is even used as a key ingredient in headache medications. However, because of the addictive properties of caffeine, headaches can also be caused by cutting back coffee consumption.

The culprit in coffee that affects cholesterol levels is not caffeine, but cafestol, a molecule found in coffee beans. Cafestol elevates cholesterol by blocking a receptor that is important to its regulation, according to researchers from Baylor College of Medicine. In fact, cafestol is “the most potent dietary cholesterol-elevating agent known,” according to Dr. David Moore, co-author of the study. Other research suggests that drinking five cups of French press coffee per day, each containing 30 milligrams of cafestol, for four weeks would raise cholesterol level by up to 8%.

Caffeine has been known to increase pressure in the eyes for a short period of time. Coffee in moderation is fine, according to the Glaucoma Research Foundation. But it is probably a good idea not to overdrink it, especially if you’re at high risk of glaucoma. Some research suggests that drinking five or more cups of caffeinated coffee a day may increase the risk of developing glaucoma, the organization notes. Additionally, caffeine may cause a spike in blood sugar levels, which may translate to blurred vision.

Caffeine can cause a temporary spike in blood pressure, and medical professionals are not sure why. One theory is that it blocks the production of a hormone that plays a role in the widening of the arteries. Another hypothesis has to do with caffeine’s effects on the adrenal glands. These glands release adrenaline, a hormone that causes a rise in blood pressure.

Drinking large amounts of coffee every day can lead to discolored, yellow, or stained teeth. It is so common, the side effect even has a name — coffee stains. Coffee — as well as tea and soda — gets trapped in the microscopic ridges of the enamel, the outer protective layer of the tooth, forming stains.

Most people drink coffee as a pick-me-up drink. Chronic and excessive caffeine intake, however, may deplete energy levels after the drink’s effects wears off, according to a study of the effects of energy drinks, in which the major stimulant ingredient is caffeine. Researchers found excessive daytime sleepiness to be common the day after energy drink consumption. Caffeine triggers the sympathetic nervous system (fight or flight response), which is OK in the short-term. When it is activated repeatedly over a time, the body gets no chance to rest, leading to fatigue.

Five cups of coffee a day or more in people who also feel high levels of stress may cause them to hear things, according to a study conducted by Melbourne’s La Trobe University. The study was initially researching why people who were never diagnosed with schizophrenia were showing symptoms of the condition.

A nine-month long study of 40 male rats conducted by researchers at the University of British Columbia, Canada, suggests that coffee may result in workers getting lazier. Researchers say the findings may apply to humans as well, especially people who use stimulants to stay alert for a long period of time, such as long-distance truck drivers.

People drink coffee to boost their alertness. Caffeine increases adrenaline levels, and when taken in high enough amounts — and these amounts vary from one person to another — jittery sensations are not uncommon, and people may feel jumpy, according to the FDA. Getting jitters and tremors as a result of excessive coffee consumption even has a name — caffeinism.

Studies conducted so far do not establish a definitive link between caffeine and muscle cramps, but some research shows a possible connection. Stimulants can cause any muscle in the body to twitch, and coffee is a stimulant. Caffeine triggers the nervous system, which controls the contraction of skeletal muscle through nerve cells. Consumed in high amounts, caffeine can cause involuntary spasms of muscle fibres across the body, according to research out of Radboud University Nijmegen Medical Centre in the Netherlands.

Digestive issues, more specifically diarrhea, are possible side effects of drinking too much coffee. Coffee, and other beverages that have caffeine, may have a laxative effect in some people, if you drink more than three cups a day.

Coffee — or the caffeine in it — has been shown to interfere with the body’s absorption of iron. Skipping tea and coffee drinks with meals is a common advice for anemic people. Hemoglobin, a protein in red blood cells that carries oxygen throughout the body, contains iron. Iron deficiency means less oxygen gets to the body’s cells, resulting in fatigue, weakness, and pale skin.

A study at the University of Western Australia in laboratory mice that aimed to show how coffee intake is beneficial to cardiovascular function ended up demonstrating that excessive caffeine consumption — the equivalent of five or six cups of coffee per day — may be linked to metabolic syndrome, which is a combination of high blood pressure, high blood sugar, excess belly fat, and high cholesterol levels. More specifically, the polyphenols, which are chemicals naturally found in plants, in the coffee made the mice retain fat in the cells. The authors do say that it is still OK to drink coffee in moderate amounts.

Doctors are not sure exactly why, but research has shown that excessive coffee drinking, which means high consumption of caffeine, may lower insulin sensitivity, which can lead to excessively high blood sugar level because the body cells don’t absorb as much glucose. (This can also be a sign you might have diabetes.) This is also why coffee may be a problem for diabetics as caffeine makes it harder to control blood sugar levels. (Insulin is the hormone that helps the body turn sugar into energy.)

Drinking too much coffee can cause nausea, according to the FDA. Caffeine increases the production of stomach acid, which may lead to nausea, in addition to stomach pain and acid reflux. Those who try to reduce or stop caffeine consumption may also feel nausea. Caffeine is a mental stimulant, a drug that can be addictive when consumed excessively over a long period of time, and nausea is not an uncommon symptom of withdrawal from caffeine, according to WebMD. The body struggles with the sudden change of not getting the amount of caffeine it is accustomed to.

Drinking too much coffee every day can sometimes cause hypokalaemia, a low level of potassium in your bloodstream, according to research conducted in Shinohara Hospital, Japan. Potassium is an electrolyte that carries signals to the nerves and muscles in the body. Common symptoms of low potassium levels are weakness and fatigue.

While hyperhidrosis, or excessive sweating, is not a very common sign of drinking too much coffee, it is possible among people who have higher sensitivity to caffeine. After all, caffeine is a stimulant. It triggers the nervous system and speeds up thermogenesis, the process of producing heat. The internal body temperature exceeds its set point, causing people to sweat.