Some patients in the clinical trial suffered an increased heart rate and a condition called metabolic acidosis, which can lead to hyperventilation, fatigue and anorexia.

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"Your muscles get cold and are instantly paralyzed by the hyperventilation, and you can become very weak, " says Dr. Thomas Traill, a cardiologist and professor of medicine at Johns Hopkins University School of Medicine.

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Nobody died of hyperventilation in the press.

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