High blood pressure, sleep disturbances, and feelings of anxiety are side effects of coffee that signal it may be time to stop drinking it.
Coffee contains caffeine, a stimulant of the central nervous system that helps fight fatigue and boosts energy. It can also improve concentration and provide various health benefits. However, caffeine tolerance varies from person to person. Consuming excessive amounts can lead to several side effects, so it’s important to watch for warning signs.
High Blood Pressure
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Coffee can cause a temporary increase in blood pressure after consumption. A review of 34 studies found that consuming 200–300 mg of caffeine (about 1.5–2 cups of coffee) led to an average rise of 8 mmHg in systolic and 6 mmHg in diastolic blood pressure.
People with hypertension should avoid drinking coffee. However, other studies suggest the effect of coffee on blood pressure can vary depending on an individual’s genes.
Elevated blood pressure increases the risk of heart attack and stroke by damaging arteries over time and restricting blood flow to the heart and brain. Researchers note that caffeine’s effect on blood pressure is usually temporary.
Acid Reflux
Coffee supports liver health and may help prevent disease. One study found that drinking more than two cups per day was linked to a lower rate of liver scarring and liver cancer in people with liver disease.
Despite these benefits, caffeine can trigger acid reflux by relaxing the lower esophageal sphincter, allowing stomach acid to flow back up. Other caffeinated drinks like tea and soda are also associated with a higher risk of gastroesophageal reflux symptoms.
Consuming large amounts of caffeine can also lead to loose stools or even diarrhea in some people.
Sleep Disturbances
Because of its high caffeine content, drinking coffee within six hours of bedtime can disrupt sleep. Normally, the feeling of sleepiness occurs when adenosine builds up in the brain. Caffeine blocks adenosine, reducing drowsiness after consumption.
If you cannot give up coffee entirely, limit your intake to the morning and keep the amount moderate.
Anxiety
Caffeine increases alertness by blocking adenosine’s effects, but at higher doses it can cause feelings of anxiety and nervousness. Drinking too much coffee may lead to a rapid heartbeat, trembling, headaches, and insomnia.
People with anxiety disorders are particularly sensitive to these effects.
Weight Gain
Coffee can influence fat storage and support gut health, both of which may help with weight management. However, for some people, drinking coffee initially suppresses appetite, leading them to skip meals or snacks.
When this temporary feeling of fullness wears off and the stomach is empty, intense hunger may set in, causing overeating at the next meal.