Urine is produced in the kidneys. When you take in fluid or food, it passes from your digestive system, into your circulatory system, and into your kidneys where it is filtered. The kidneys then get rid of waste products and extra fluid through the urine.
The ureters are tubes that connect the kidneys to the bladder. The bladder empties the urine via the urethra, the tube you urinate through.
Ideally, your urine would be a pale yellow color. This would indicate you’re hydrated. Urine naturally has some yellow pigments called urobilin or urochrome. The darker urine is, the more concentrated it tends to be.
Dark urine is most commonly due to dehydration. However, it may be an indicator that excess, unusual, or potentially dangerous waste products are circulating in the body. For example, dark brown urine may indicate liver disease due to the presence of bile in the urine.
Bloody, or reddened urine is an indication of other potential problems, including direct injury to the kidneys. If you have these symptoms, it’s important to see a doctor.
Conditions associated with dark urine include:
- biliary obstruction
- bladder stones
- bladder cancer
- liver disease
- kidney cancer
- pancreatic cancer
- side effects of blood-thinning medications
- bladder or kidney stones
Excess or overly strenuous exercise can also contribute to dark urine. Intense exercise can cause muscle injury that causes your body to release waste products in excess. The results can be urine that is either pink or cola-colored.
Sometimes it’s difficult to tell the difference between dark urine due to dehydration or due to other causes. Dark urine due to dehydration is usually amber or honey-colored.
Dark urine due to other causes can be tinged with brown or red. Some people have urine that appears almost syrup-like. This is the case when a person has liver or kidney disease.
If you’re dehydrated, you can have additional symptoms besides dark urine. Examples include:
- dizziness or lightheadedness
- dry mouth
- dry skin
If you drink additional water and your urine becomes lighter, you can tell dehydration was the cause of your dark urine.
Outside factors that affect urine
Sometimes dark urine doesn’t have anything to do with hydration or overall health. Instead, it’s related to something you ate or drank or a medicine you took. If your urine is dark, think back to what you’ve eaten. If you’ve had beets, berries, rhubarb, or fava beans, these can all cause your urine to appear dark.
Some medications can cause dark urine. Usually your doctor will let you know beforehand that this is a possible side effect. Some examples of medicines known to do this include:
- laxatives with senna
- chemotherapy drugs
- warfarin (Coumadin)
When to call your doctor
You should seek medical attention if you see blood in your urine, or experience dark urine that does not go away after drinking water. It’s very important to know the exact cause of your symptoms.
If you have dark urine accompanied by intense pain, especially in your back, you may have kidney stones or a urinary tract infection. If you can’t see your doctor right away or if the pain and any other symptoms get worse or are accompanied by nausea, vomiting, and a high fever, seek immediate medical attention.
Diagnosis and treatments
If you’re experiencing dark urine that isn’t caused by dehydration or is a side effect of your medication, you’ll need to have a comprehensive evaluation by your doctor. They will need your detailed medical history and you will need to have a physical examination and urinalysis.
A urinalysis involves taking at least a two-ounce sample of your urine. A laboratory will test the urine for the presence of several things, which could indicate the presence of an underlying medical condition. Examples include:
- red blood cells
- white blood cells
A lab will give a report based on three components.
- a visual exam will read if the urine is clear, cloudy, and concentrated, along with its color.
- chemical tests include information about bilirubin, blood, ketones, proteins, and glucose.
- a microscopic examination tests for the presence of bacteria.
Ideally, the urine sample will come from the first urine you produce in the morning. This urine is most likely to show abnormalities if there are any because it is more concentrated than other urine you produce over the day.
If your urinalysis reveals unusual results, your doctor may order more targeted tests. These tests may include blood testing or a urine culture, which attempt to identify the type of bacteria in your urine. Also, a complete blood count or comprehensive metabolic panel can help your doctor identify if your kidney or liver function is compromised.
Treatment will depend on your medical history, symptoms, and the results of any laboratory studies and other diagnostic tests.
Preventing dark urine
If your urine color is due to medicines you take, you should continue taking them based on your results. Always talk to your doctor if you are concerned about your urine color in relation to the medicines you take. You can also avoid foods known to cause dark urine.
If your dark urine is due to insufficient fluid intake, you should start drinking more water. According to Harvard University, you should ideally make about 6.5 cups of urine a day and void anywhere from four to eight times.
Try drinking an extra cup of water after waking up. You can buy a large container to hold water and keep it with you at all times to make sure you stay hydrated. However, if your urine is so pale that it is almost clear, this could be a sign you are drinking too much water.
Any change in the color of the urine not due to eating certain foods or taking certain medications should be reported to your doctor. And contact your doctor immediately is you see blood in your urine.