Black Urine - a rare condition of urinating black-colored pee. It is sometimes caused by genetic disorders, various types of medications, or metabolic disorders.
Alkaptonuria is a rare inherited genetic disorder of phenylalanine and tyrosine metabolism. As with many metabolic conditions, when a certain chemical is over-produced or there is simply an over-abundance of it, the body attempts to remove it as waste through stool or urine. Patients with Alkaptonuria experience an accumulation of a toxic tyrosine byproduct called homogentisic acid. When this acid accumulates in the blood, it is excreted in urine, giving the urine a black color.
Relatively normal urine which has become quite dehydrated, or full of other poorly metabolized chemicals can sometimes appear black, when it is actually brown urine. While brown urine isn't a great thing either, the chemical makeup and pigmentation of the two are quite different. To tell what chemicals may be appearing in your urine, you may perform urine tests, some of which can even be done in the privacy of your own home and sold over-the-counter like the urine dipstick test.
The common tint of healthy urine is yellow. Yellow urine is what just about all of us expect to see when we pee. Sometime the pee changes color to darker or lighter, depending on our diets, lifestyles, time of day, genetics, our overall health, and more. Lighter urine tends to be a result from over-hydration, or urinating before the pee had time to sit in the bladder and mix with other chemicals. The yellow color comes from a chemical called urobilin which is a normal and healthy occurrence.
If the urine becomes darker and can be described as Orange Urine, it may be a sign of dehydration. Orange or darkened urine is also common in the mornings when the urine has had time to sit in the bladder over-night and mix with other chemicals.
This is a pretty unusual condition, but there are many very rare causes of it. Blood in urine usually does not make it appear black, but in rare cases it may make the pee appear to be black color. Other causes of black urine may be severe poisonings from mixing various medications and alcohol for example. In such cases as poisonings, it is less an issue of a direct cause and more an instance of the body just having an extremely difficult time processing the chemicals inside it, and what comes out of it is quite chaotic.