One Manchester United fan knows exactly what is meant when people say football is a matter of life and death.
Without treatment, the 58-year-old woman is in danger of dying from stress while watching her team play.
Doctors diagnosed "Addisonian crisis", a rare and life-threatening condition caused by lack of the stress hormone cortisol.
Towards the end of high-profile matches at Old Trafford, Manchester United's home ground, the woman suffered episodes of anxiety, palpitations, panic, light-headedness and a sense of impending doom.
Symptoms were especially severe during crucial games when the outcome was in question until the last minute, according to doctors writing in the British Medical Journal.
"On these occasions, she considered leaving the stadium because she felt so unwell," wrote Dr Akbar Choudhry, from Trafford General Hospital, and colleagues.
In contrast, her symptoms were barely noticeable when the opposition was from the lower reaches of the league.
Addisonian crisis is a particularly serious manifestation of Addison's disease, which results from the adrenal glands not producing enough cortisol. It can lead to plummeting blood pressure, coma and death. The condition is difficult to diagnose because the main symptoms of fatigue, lethargy and low mood are often experienced by "healthy" individuals.
The doctors concluded: "We believe our patient was having difficulty mounting an appropriate physiological cortisol response during the big games and therefore we present this as the first description of Manchester United-induced Addisonian crisis."
The patient was on holiday for Manchester United's 6-1 defeat by local rivals Manchester City in October and was, by this time, being successfully treated with replacement cortisol. She has remained symptom-free during her team's recent tense contests against Sunderland and FC Basel.