Stroke victim’s urine turns PURPLE because of a rare chemical reaction inside her body
- The unidentified 70-year-old, from France, was in hospital after having a stroke
- She had a catheter – a tube used to empty the bladder and collect urine in a bag
- However, 10 days after she was first admitted to hospital, the urine turned purple
- Medics just outside of Paris diagnosed her with ‘purple urinary bag syndrome’
A stroke victim’s urine turned purple because of a rare chemical reaction inside her body, doctors in France have revealed.
The unidentified 70-year-old was in hospital after suffering a stroke, which left her struggling to speak and paralysed on one side.
To help her urinate, she was fitted with a catheter – a flexible tube used to empty the bladder. The urine is collected in a drainage bag.
However, 10 days after the patient was first admitted to hospital for treatment, the urine in her bag turned purple.
The unidentified 70-year-old was in hospital after suffering a stroke, which left her struggling to speak and paralysed on one side
Medics at the Hôpital de Bicêtre, on the outskirts of Paris, diagnosed her with ‘purple urinary bag syndrome’ (PUBS).
Dr Léo Plaçais and team did not find that she had a UTI but tests showed there was Klebsiella pneumoniae bacteria in her urine sample.
It is unclear how common PUBS is – but doctors say the discolouration of urine is triggered by a series of internal chemical reactions.
Some bacteria, including the kind this woman had, can break down metabolites of tryptophan – an amino acid found in food.
This produces indole, which becomes indoxl sulfate. This oxidises into blue-coloured indigo and the reddish indirubin.
The combination of indigo and indirubin gives a purple hue to the urine collection bag. However, the discolouration is completely benign.
Women face a higher risk of developing PUBS because they have a shorter urethra, which leaves them more vulnerable to catching UTIs.
The unusual tale of PUBS – first described in the 1970s – was published in the prestigious New England Journal of Medicine.
The woman’s urine returned to its normal colour after four days of intravenous hydration. She was then transferred to a separate facility.
It is not the first time MailOnline has reported on PUBS – last year Indian doctors released pictures of the same phenomenon which happened to a 70-year-old man.
The man was treated at King George’s Medical University in Lucknow, around 330 miles (531km) east of New Delhi.
He had been using the catheter in hospital for six months, ahead of planned surgery to cut away part of his enlarged prostate.