A 54-year-old warehouse worker arrived to the emergency room with numbness, weakness on his left side, and ataxia<\/a> (trouble with balance and movement), according to a case report in BMJ Journals.<\/a> He was \u201cnormally fit and well,\u201d the report says \u2014\u00a0 except for his blood pressure.<\/p>\n \u201cHis blood pressure<\/a> was sky high \u2014 about 254 over 150 millimeters \u2014 yet when you looked at him you\u2019d never know it, because he looked so well. That\u2019s why we call hypertension the silent killer,\u201d Dr. Sunil Munshi, a consulting physician at Nottingham University Hospitals NHS Trust in the United Kingdom, and senior author of the report, told CNN.<\/a><\/p>\n Getty<\/p>\n Stock image of a patient in a hospital bed.<\/p>\n Normal blood pressure for a man his age is less than 120 over less than 80, per the American Heart Association<\/a>. His numbers are classified as a \u201chypertensive emergency.\u201d<\/p>\n The blood pressure had caused \u201ca stroke in the deeper part of the brain, the thalamus, which explains the unsteadiness,\u201d Munshi told the outlet. The man, a warehouse worker from the Sherwood district of the English city of Nottingham, was admitted and treated with five different medications to make his blood pressure drop.<\/p>\n After he was discharged, his blood pressure began to increase again, leaving doctors baffled \u2014 until, as Munshi shares, he told doctors about his energy drink habit.<\/p>\n \u201cEach day he consumed eight highly potent energy drinks to stay alert for his job \u2014 two cans at four different times during the day,\u201d Munshi told CNN. \u201cEach of the drinks contained 160 milligrams of caffeine. Suddenly the diagnosis was clear.\u201d<\/p>\n The Mayo Clinic<\/a> says that up to 400 milligrams of caffeine a day \u201cseems safe\u201d for most adults; the patient was drinking more than three times that amount.<\/p>\n Too much caffeine can increase your risk of developing cardiovascular disease, according to a study from the American College of Cardiology<\/a>.<\/p>\n Shutterstock \/ New Africa<\/p>\n Stock image of the tops of energy drinks.<\/p>\n Never miss a story \u2014 sign up for\u00a0PEOPLE’s free daily newsletter<\/a>\u00a0to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.<\/p>\n He stopped drinking the energy drinks (the specific brand was not identified in the study), and his blood pressure returned to normal. But the lingering impact of his stroke and energy drink habit remain, he told his doctors, per CNN.<\/p>\n \u201cI obviously wasn\u2019t aware of the dangers drinking energy drinks were causing to myself,\u201d he said, explaining he\u2019s \u201cbeen left with numbness [in my] left hand side hand and fingers, foot and toes even after 8 years.\u201d<\/p>\n As Munshi explained, there are other ingredients in energy drinks that can contribute to health problems. \u201cEnergy drinks that contain caffeine plus taurine<\/a> produce significantly higher blood pressure than caffeine alone,\u201d he said. \u201cThey also contain high levels of glucose \u2014 we know sugar damages the blood vessels in diabetes which leads to heart damage.\u201d<\/p>\n![\"Getty](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2025\/12\/a8be4b38288c95f6e8939843bc7e5394.jpeg\"\/)
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