Common and Unusual Causes of Dark Urine

Dark-colored urine can reflect problems with a wide range of body systems. Urine that is a bit deeper yellow than usual often simply signifies mild dehydration, but notably dark yellow and other colors could be early signs of something more serious, such as kidney infections. Dark urine can also be a side effect of medication or improper catheterization. Urine that looks bloody is particularly worrisome and should prompt a visit to a doctor.

Blood-Red Urine

Hematuria, the presence of blood in the urine, has many origins and should be investigated promptly. It could be a urinary tract infection (UTIs) or another infection. Less commonly, it can signify cancer, benign prostate hyperplasia (BPH), and physical trauma to the kidneys. If there is no known reason for blood in the urine (such as menstruation), seeing a doctor is advisable. Offer the medical practitioner as much information as possible about any injuries, how long the urine has been this color, and any other symptoms.

Tea-Colored Urine

This color is often confused with hematuria, but urinalysis test results are different in this case. The cause is generally myoglobinuria, a condition that causes muscle cells to release an oxygen-carrying substance called myoglobin during muscle destruction. Alcohol and drug abuse or physical trauma can set this process in motion. However, some medications and foods can also cause brown discoloration. For example, the urine can turn brown or tea-colored after eating large quantities of rhubarb.

Dark Brown Urine

This color is often the result of bile from the liver entering the urine stream — bilirubinuria. It can indicate liver conditions or cholestatic liver disease, which can lead to cirrhosis. This color may be confused with hematuria, but diagnosis and treatment follow a different path.

Black Urine

This ominous color can be a sign of a serious condition, paraphenylenediamine toxicity, which is caused by ingredients in some hair dyes. Consequences include rhabdomyolysis or a breakdown of muscle tissue that causes toxins in the blood, leading to kidney damage or even failure. People with this condition often require dialysis. In some cases, the cause could be alkaptonuria, an inherited condition that can cause the urine to turn black when exposed to air.

Orange Urine

This color is fairly common in urine, as it is a typical result of medication used to treat the symptoms of urinary tract infections. If the person has not taken such medications recently, the color might also be due to a combination of normal yellow urine and blood in the urine stream, which requires medical investigation. Certain foods, including large quantities of carrots, can also give the urine an orange tint.

Cloudy and Dark Urine

Cloudy urine can occur when the urine is also dark. Pyuria is the most common cause and results from the placement of a chronic indwelling catheter. This can lead to bacteria development, specifically bacteriuria, followed by an increase in white blood cells to fight the infection. Sometimes, pus may drain through the urine stream. Pyuria requires urgent treatment and the individual may need to have their catheter replaced with a temporary type. Other common causes of the condition are urinary tract infections, sexually transmitted diseases, and kidney stones.

Dark, Solid Matter in Urine

This is most likely to occur after a procedure called lithotripsy, where a doctor uses ultrasound shock waves to break up stones lodged in the tract between the kidney and the bladder and ureters. Such treatment sometimes requires a stent into the kidney to keep urine flowing until these pieces have exited.

Purple Urine

It is possible for urine in a collection bag to turn purple, though this is a fairly rare situation. A chemical reaction between organisms in the body that produce indoxyl phosphatase and the materials in the catheter or urine collection bag cause the effect. Medical professionals refer to this as “purple urine bag syndrome” or PUBS. A condition called porphyria can also give the urine a purple tint.

Dark Green Urine

Dark green urine flow may occur after a patient receives a certain type of anesthesia during surgery. It is a normal result of the kidneys processing the medication and usually develops when the patient requires quite a large quantity. Some UTI medication can also cause this color to appear.

Dark Yellow Urine

Normal urine can be a light yellow color, but if it is too dark, it can indicate dehydration from drinking few fluids or from diarrhea or vomiting. Dehydration is serious, and if increasing fluids does not resolve urine color and any other dehydration-related symptoms, the individual may require medical attention. Some medications and foods can also cause the urine to be darker than normal.