What disease is purple urine

Under normal circumstances, human urine should be light yellow, because human urine contains some urea, which is yellow. Some people will have dark yellow urine if they drink less water. In fact, human urine can also reflect many diseases of the human body. Some people find that their urine is purple. Next, let me tell you what disease causes purple urine.

1. What is Purple Urine Bag Syndrome (PUBS)

Purple urine bag syndrome (PUBS) is a relatively rare clinical phenomenon. It refers to the appearance of pigmentation in the catheter or urine bag after indwelling catheterization, which appears purple (the color can range from light purple to dark purple). It is common in patients with long-term indwelling catheters, especially elderly female patients, who also have urinary tract infections. The risk factors include: female, elderly, indwelling catheter, chronic constipation, chronic kidney disease, azotemia, high-protein diet, etc.

2. Why is urine purple?

The most significant characteristic of PUBS is the purple color of urine (light purple to dark purple). In rare cases, blue or brownish red urine can also be seen. The main reason why urine appears purple is due to the mixture of pigments of indigo and indirubin, the end products of intestinal indole metabolism. Tryptophan in food is metabolized into indole by intestinal bacteria, absorbed into the blood through the portal vein, metabolized into indole sulfate in the liver, excreted in the urine through circulation, and broken down by sulfatase or phosphatase secreted by urethral bacteria to produce blue indigo and red indigo red. When the two are mixed, the urine appears purple.

3. Biochemical characteristics of PUBS urine

1. pH value: Since sulfatase and phosphatase work better under alkaline conditions, urine is usually alkaline, with a pH value greater than 7.0 (acidic urine also exists, but it is less common)

2. White blood cells: Due to urinary tract infection, a large number of white blood cells are usually seen in the urine

3. Bacteria: A large number of bacteria can be seen in urine, and the cultured bacterial concentration is above 105 CFU/mL. Common bacteria include Pseudomonas aeruginosa, Proteus mirabilis, Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Providencia, Enterococcus, etc. Although urinary tract infections are common in patients with indwelling urinary catheters, not every bacterium produces sulfatases and phosphatases, and purple urine bag syndrome is uncommon.

IV. Treatment of PUBS

The treatment of PUBS includes replacing the urinary catheter and urine bag, selecting sensitive antibiotics to control urinary tract infection based on the results of bacterial culture identification and drug sensitivity test, and correcting urine pH.