If You Can Smell This, You're Drinking Too Much Caffeine, Study Finds


If in your kitchen, one cup of coffee has a tendency to turn into three or four, chances are your caffeine habit has spiraled out of control. But how can you know for sure? Researchers from the U.K.'s University of Portsmouth have found that there's one way to detect an over-reliance on your morning cup of joe: paying close attention to whether or not you notice the smell of a weak cup of coffee.

The team set out to determine the differences in how people respond to the smell of coffee depending on whether or not they were big coffee consumers. They ultimately discovered that habitual coffee drinkers are far more sensitive to the scent of coffee, and can sniff out even tiny traces of caffeine in the weakest cup of joe. "We found the higher the caffeine use, the quicker a person recognized the odor of coffee," explained Lorenzo Stafford, PhD, an olfactory expert and co-author of the study.

Stafford and his team also found that those with strong coffee cravings had a more finely attuned ability to detect caffeine: they were both more sensitive to the smell of coffee and more quickly able to identify the scent. "Those higher caffeine users were able to detect the odor of a heavily diluted coffee chemical at much lower concentrations," said Stafford, "and this ability increased with their level of craving. So, the more they desired caffeine, the better their sense of smell for coffee."

Their findings were consistent with studies on other types of drugs, which have  determined that trace amounts of various substances can trigger cravings in addicts.

So, the next time you smell the faintest whiff of coffee from a faraway coffee shop or notice that a watered down cup of coffee smells suspiciously strong to you, it's worth asking whether your caffeine habit gone too far. Read on for more signs that you're drinking too much caffeine, and for more on how your sense of smell might signal a problem, check out If You Can't Smell These 2 Things, You Might Have COVID.



Coffee can give you more energy, and if you've had a cup too many, with that energy can come a surplus of sweat. That's because caffeine is a stimulant that accelerates functions in your nervous system, raises your heart rate, and gets your blood pressure pumping—all of which can make you perspire.

While moderate servings of caffeine shouldn't trigger the problem, Mayo Clinic points out that consuming more than 400 milligrams—or four cups—per day can send your system spiraling, leading to this and other side effects. And, looking to minimize sweating? Here's Why You Don't Have to Sweat to Get a Great Workout.

Heart palpitations


According to Arun Sridhar, MBBH, MPH, a cardiac electrophysiologist and specialist in heart rhythm disorders, many people who have ingested too much caffeine will notice heart palpitations. "On a high caffeine dose, people will feel a lot of skipped beats, thumping or a noticeably fast heart rate. If your heart rate is irregular or stuck at a very high rate, if your symptoms just feel overwhelming or if you are dizzy or faint, then you should go to the emergency room," Sridhar recently told UW Medicine.



Not only do people often develop nausea after drinking too much caffeine—they also develop nausea when they're in withdrawal from the substance. If you experience this double-whammy of discomfort it likely means your stomach is producing too much acid in response to the stimulant, and it's time to scale back. And for more on stomach symptoms, Here's What Your Indigestion Is Trying to Tell You.



Caffeine literally releases adrenaline into your system, causing a "fight or flight" reaction that could leave you on edge. In fact, the result can sometimes be so severe and pronounced that caffeine-induced anxiety disorder is listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM) as one of four caffeine-related mental disorders.

If you notice increased anxiety or restlessness after your second or third cup of coffee, it's officially time to cut back.