Man’s Stroke Tied to Extreme Energy Drink Use, Doctors Say

Harvard Health notes that excessive consumption—especially among teens and young adults—can cause dehydration, irregular heart rhythms (arrhythmias), and high blood pressure.

Kelly McBride Ni

Published: 12/11/2025, 5:41:48 PM EST

Man’s Stroke Tied to Extreme Energy Drink Use, Doctors Say — A red bull and other energy drinks in a shelves of a supermarket, in Bourgueil, France, on Dec. 26, 2024. (Magali Cohen/ Hans Lucas via AFP)

A man in his 50s who suffered a stroke and months of hypertension saw his blood pressure return to normal only after stopping his daily intake of nearly eight energy drinks to stay alert for his job, according to a case report published in Neurology.

The patient, described as normally healthy, arrived at the hospital with left-sided weakness, numbness, and ataxia. Upon admission to the hospital, his blood pressure was 254/150 mm Hg, according to the Neurology report from England, authored by Dr. Martha Coyle and Dr. Sunil Munshi.

A reading of 254/150 mmHg is extremely high and represents a severe hypertensive crisis and needs immediate medical attention. Normal is around 120/80 mmHg, and any reading over 180/120 mmHg is considered a medical emergency.

Imaging confirmed an ischaemic thalamic stroke—a blood clot blocking an artery to the thalamus, a brain area that relays signals and controls consciousness, movement, and memory.

Although hospital treatment reduced his systolic blood pressure to 170 mm Hg, it spiked again after discharge and stayed dangerously high for months, even with five blood pressure medications that lower blood pressure.

According to MedPage Today, clinicians discovered the cause after asking about the patient’s daily habits. Coyle and Munshi reported that he drank eight high-caffeine energy drinks daily, each containing 160 mg of caffeine, totalling 1.2–1.3 g of caffeine—over three times the recommended maximum of 400 mg set by NICE (the National Institute for Health and Care Excellence) for UK health guidelines.

When he stopped the energy drinks, his recovery was rapid. As the authors wrote: "One week after stopping the drinks, his average BP readings showed 120–130 mm Hg systolic… and he was able to be completely weaned off all medications after 3 weeks." They concluded it was "likely that the patient's consumption of highly potent energy drinks was, at least in part, a contributive factor to his secondary hypertension and in turn his stroke."

According to a Harvard Health’s article on energy drinks, caffeine content varies widely in energy drinks, ranging anywhere from 6 to 242 mg per serving, and most products include lots of sugar, herbal additives, and stimulants.

Harvard Health notes that excessive consumption—especially among teens and young adults—can cause dehydration, irregular heart rhythms (arrhythmias), and high blood pressure.

The Food and Drug Administration (FDA) recommends a daily caffeine limit of no more than 400 mg for adults. "That's about two to three 12-fluid-ounce cups of coffee — as an amount not generally associated with negative effects. However, there is wide variation in both how sensitive people are to the effects of caffeine and how fast they eliminate it from the body," states the FDA.

For teens and children, "Medical experts advise against energy drinks for children and teens because of the levels of sugar and caffeine, according to the American Academy of Pediatrics," states the FDA. "Too much caffeine in children and teens can cause increased heart rate, heart palpitations, high blood pressure, anxiety, and lead to sleep problems, digestive problems and dehydration."