Dark Urine: What It Means

What normal urine looks like

Urine gets its yellow color from urochrome, a pigment made when the body breaks down old red blood cells. The more water in the urine, the paler it looks. Healthy urine ranges from pale straw to light amber. The first urine of the morning is usually darker because you have not drunk overnight.

Dark urine color chart

For other color and smell changes, including green, blue, cloudy or foul-smelling urine, see unusual urine color or odor.

Common causes of dark urine

Dehydration

Dehydration is by far the most common cause. Others signs include thirst, a dry mouth, passing less urine, headache and tiredness. Exercise, hot weather, vomiting, diarrhea, fever and alcohol all increase fluid loss. Urine should return to pale yellow within hours of drinking more.

Foods, vitamins and medicines

• Foods: large amounts of fava beans, rhubarb or aloe can darken urine.
• Vitamins: B vitamins and riboflavin turn urine bright, fluorescent yellow.
• Medicines: metronidazole, nitrofurantoin, chloroquine, methocarbamol, levodopa, some laxatives containing senna, and the urinary pain reliever phenazopyridine (orange).

Serious causes of dark urine

Liver and bile duct problems

When the liver cannot process bilirubin, or bile cannot drain into the gut, bilirubin spills into the urine, turning it tea-brown. This usually comes with:

• jaundice: yellow skin and whites of the eyes
• pale, clay-colored stools
• itching
• upper right abdominal pain, nausea or fever, depending on the cause

Causes include hepatitis (viral, alcohol- or drug-related), gallstones blocking the bile duct, cirrhosis, and pancreatic or bile duct cancer, which classically causes painless jaundice with weight loss.

Muscle breakdown (rhabdomyolysis)

Rhabdomyolysis releases a muscle protein, myoglobin, into the blood. It turns urine brown or cola-colored and can damage the kidneys. Triggers include extreme exercise (especially when unaccustomed or in heat), crush injuries, prolonged immobility after a fall, heat stroke, seizures, some statins and recreational drugs. Muscle pain, swelling and weakness are typical. It needs urgent treatment with IV fluids.

Breakdown of red blood cells (hemolysis)

When red blood cells break down quickly, hemoglobin reaches the urine and darkens it. Causes include G6PD deficiency triggered by fava beans, infections or certain medicines; autoimmune hemolytic anemia; transfusion reactions; and malaria. Fatigue, pale skin, breathlessness and jaundice are common.

Blood in the urine

Old or small amounts of blood can make urine brown rather than red. Causes include urinary infections, kidney stones, kidney inflammation (glomerulonephritis, often with cola urine, swelling and high blood pressure), and bladder or kidney cancer. See blood in urine.

Porphyria

Porphyria is a rare group of inherited disorders. In acute attacks, urine can turn reddish-brown or darken further on standing in light, with severe abdominal pain.

How doctors find the cause

Your doctor will ask about fluid intake, color changes, foods, medicines, exercise, injuries, alcohol, travel and other symptoms. They will check your skin and eyes for jaundice and examine your abdomen and muscles.

Tests may include:

• Urine dipstick and microscopy: look for bilirubin, blood, protein, infection and red cells. A dipstick positive for "blood" without red cells on microscopy suggests myoglobin or hemoglobin.
• Blood tests: liver function, kidney function, creatine kinase (CK) for muscle damage, blood count and hemolysis markers.
• Imaging: ultrasound of the liver, bile ducts and kidneys.

Treatment

Treatment depends on the cause:

• Dehydration: drink fluids steadily until urine is pale. Use oral rehydration solution after vomiting or diarrhea.
• Medicine-related: discuss alternatives with your doctor; do not stop prescribed medicines without advice.
• Liver and bile duct disease: treating hepatitis, removing gallstones from the bile duct (ERCP), or treating tumors.
• Rhabdomyolysis: hospital IV fluids to protect the kidneys.
• Hemolysis: avoiding triggers, treating infection, and sometimes steroids or transfusion.

Frequently asked questions

Does dark urine mean liver problems?

Usually not. Dark yellow urine is most often from dehydration. Brown, tea-colored urine together with yellow eyes or skin, pale stools or itching suggests a liver or bile duct problem and should be checked promptly with blood tests.

What causes brown urine?

Brown urine can come from severe dehydration, certain foods and medicines, liver or bile duct disease, muscle breakdown (rhabdomyolysis), red blood cell breakdown or old blood. Brown urine that does not clear with fluids needs medical tests.

Is dark urine in the morning normal?

Yes. Morning urine is concentrated because you have not had fluids overnight, so it is often darker. It should lighten during the day as you drink.

How quickly does urine get lighter after drinking water?

If dehydration is the cause, urine usually becomes paler within 1 to 3 hours of drinking enough fluid. If it stays dark for 2 days despite drinking well, see a doctor.

Can exercise cause dark urine?

Yes. Hard exercise in heat causes dehydration and darker urine. Very intense or unaccustomed exercise can also cause rhabdomyolysis, with cola-colored urine and severe muscle pain. That is a medical emergency.