Published on
10/12/2025 – 7:00 GMT+1

A “previously fit and well” UK man had a stroke after downing eight energy drinks per day, prompting doctors to warn that the popular beverages may raise cardiovascular risks.

The man, who is in his 50s, wasn’t a smoker and did not drink alcohol or abuse drugs.

He showed up at the hospital after his left side suddenly went numb and he had trouble with balance, walking, swallowing, and speech – classic stroke symptoms. He’d had a stroke in the thalamus, the part of the brain involved in movement and sensory perception.

While he seemed otherwise healthy, the patient’s blood pressure was 254/150 mm Hg (millimetres of mercury), which is considered extremely high.

Doctors gave him medication to lower his blood pressure, but once he returned home, it rose again and remained elevated even after they increased the dosage.

That’s when they learned he drank, on average, eight energy drinks per day, each of which contained about 160 milligrams (mg) of caffeine. That brought his daily caffeine intake as high as 1,280 mg, more than three times higher than the recommended maximum of 400 mg.

After doctors asked the patient to stop consuming energy drinks, his blood pressure returned to normal and he no longer needed medication – but he never regained full feeling on his left side, according to the case study published in BMJ Case Reports.

“I obviously wasn’t aware of the dangers drinking energy drinks were causing to myself,” the patient said, according to the report.

“[I] have been left with numbness [in my] left hand side hand and fingers, foot, and toes even after eight years.”

The doctors, Martha Coyle and Sunil Munshi from Nottingham University Hospitals NHS Trust, are now calling for tighter restrictions on energy drinks and more awareness of the potential cardiovascular risks – particularly among younger people, who are thought to be at lower stroke risk overall.

“It is possible that both acute and chronic intake of [energy drinks] may increase [cardiovascular disease] and stroke risk, and importantly, this may be reversible,” they said, though they acknowledged that “the current evidence is not conclusive.”

The patient represents just one case, and more data would be needed to prove that energy drinks actually raise heart health risks.

But the doctors argued that because stroke and heart disease are so common, more should be done to curb potential risks.

“In patients with unexplained hypertension, clinicians should enquire about consumption of energy drinks,” they said.