The appearance of black urine can be very scary, however, in most cases, it is caused by minor changes such as the ingestion of some foods or the use of new medicines prescribed by the doctor.
However, this urine color may also be caused by more serious health problems such as porphyria or even, skin cancer. Thus, if black urine appears for more than 2 days or if it is accompanied by other symptoms, it is advised to go to the general practitioner to identify the cause and initiate appropriate treatment.
If your urine is not black, but only dark, see what the causes may be.
3 leading causes of black urine
Changes in urine color usually have 3 major types of causes
1. Intake of some foods
This is the least worrisome cause of the appearance of black urine and is related to the exaggerated intake of foods with natural or artificial dyes such as:
- Rhubarb : usually causes only a darker urine, but in very high amounts it can cause urine to turn black;
- Broad beans : they are rich in L-dopa, a substance that leaves the urine darker, brown or black;
- Aloe, in the form of juice, for example: contains aloe, a substance that can leave the urine black.
In addition, foods rich in sorbitol such as apples, pears, peaches and plums, as well as unsweetened foods like chewing gum, ice cream or candy can also change the color of urine to black. However, when the surbitol is in very high amounts it also causes stomach pains, cramps and diarrhea.
The use of copper cooking pots can also cause black urine in some people, especially those who can not metabolize the mineral, eliminating it in high quantities in the urine, which leaves the urine very dark.
2. Use of medicines or chemicals
This is the second leading cause of urine color change and usually occurs due to frequent contact with some chemicals in various medications. Some of the remedies or chemicals that can cause black urine are:
- Fenacetin : is present in many painkillers and when used frequently leads to the destruction of hemoglobin in the blood, which is eliminated in the urine, causing very dark coloration;
- Levodopa : is a medicine used in Parkinson's treatment that contains L-dopa, which can leave the urine very dark;
- Phenol : this substance usually enters the body through repeated contact with disinfectant or cleaning products, therefore it is recommended to use gloves when using this type of products;
- Laxatives : some contain shell or senna, two substances that when used in excess can leave the urine very dark;
- Chloroquine and Primaquine : are remedies used in the treatment of malaria that can cause black urine, as a side effect;
- Furazolidone, Metronidazole or Nitrofurantoin : are antibiotics that can change the color of the urine, being able to vary between dark red and black;
- Methyldopa : It is a high blood pressure medicine that releases metabolites in the urine that, when they come in contact with the bleach used to clean the toilet, can cause black urine.
In some cases, iodopovidone, which is a liquid widely used to clean some wounds, when used on many large areas of skin can be absorbed by the body and eliminated in the urine, causing the black color.
When the problem is caused by the use of these medicines, you should consult the doctor who prescribed them to adapt the dose used or to change the medicine.
3. Diseases
One of the main health problems that can cause the appearance of black urine is skin cancer, because this disease causes an exaggerated production of melanin, the substance that causes the dark coloration of the skin. When present at high levels, melanin is eliminated by the body through the urine, leaving it dark brown or black.
However, other more rare diseases such as Alkaptonuria, porphyria cutanea or Black Water Fever can also cause black urine. Thus, if the color change is not caused by a food or by the use of the remedies listed above, it is advisable to quickly consult a general practitioner to identify if there is any disease that is causing the problem in order to initiate appropriate treatment.
In addition, problems in the liver, such as hepatitis or cirrhosis, kidney infections or diseases caused by viruses such as Haff's disease, can make urine very dark in color, such as brown or red, and can easily be mistaken for black urine.
