Black urine disease :-

 This is a disease also called as Alkaptonuria . In this disease the colour of the urine of black , as the name suggests .

Causes :- 

• Deficiency of homogentisate oxidase is main cause of black urine disease .
• The defeciency of homogentisate causes some defect in the metabolism of phenylalanine and tryptophan .

Characteristics :-

• Blackish appearance of the urine is because of accumulation of homogentisate , which afer getting exposed to outer environment  ( mainly oxygen )gets converted into black colour .

Diagnosis :-

•  The diagnosis can be done by observing the colour of urine , if it is black then we can identify it as alkaptonuria .
• We can also give the urine for lab testing and can find by doing tests .
• Increased levels of homogentisic acid / homogentisate .

Treatment :- 

• Actually it is not a serious problem so there is no specific treatment foe it . 
• However , we can treat it by decreasing the content  / amount of homogentisate in the food .

Complication :- One of the complication of alkaptonuria is :

• Accumulation of alkaptone in the soft tissues in our body called ochronosis .