Dark urine and weight loss occurring together are symptoms that should not be ignored; both of these can indicate serious medical conditions, usually involving the liver or kidneys. Normal urine is the color of yellow straw, and doctors generally advise that you consult a health care provider if you experience any unexplained discoloration of urine, especially if it continues for more than a day or two or happens repeatedly. Unexplained weight loss is also a reason for a doctor visit.
It is possible that there is an innocuous reason for the dark urine and loss of weight. Some medications and foods -- including beets, blackberries and food colorings -- can discolor urine. Weight loss may simply be a result of being more active or cutting back on calories. But unless you are sure that you can explain your symptoms this way, you should see your doctor.
Dark urine and loss of appetite that leads to weight loss -- along with headaches, nausea, fatigue, body aches and jaundice, or yellowing -- are symptoms of hepatitis A, a highly contagious liver infection. These symptoms usually appear about a month after infection. You can contract hepatitis A by drinking contaminated water or by eating food that has been prepared by a restaurant worker infected with the disease; you can also get it from shellfish harvested from polluted water. In addition, you can get hepatitis A by having sex or close contact with someone who is infected. Although there is no treatment for hepatitis A, most people recover completely on their own.
Hepatitis B has symptoms similar to those of hepatitis A. It is transmitted by sexual contact and by sharing needles. Health care workers can also be infected by accidental needle sticks. In addition, the disease can be transmitted during childbirth from mothers to infants. In the acute form of hepatitis B -- more common in adults -- the body usually clears the virus on its own within six months, leading to complete recovery. The chronic form is more common in infants and children, but often symptoms are absent. They may surface decades later, however. Chronic hepatitis B can cause cirrhosis, liver cancer, liver failure and infection with hepatitis D, another form of the hepatitis virus. Doctors treat the chronic form of hepatitis B with antiviral medications.
Hepatitis C has symptoms similar to those of the A and B viruses but also causes pale or clay-colored stools. It can be spread by sexual contact, sharing needles, getting a tattoo with a contaminated needle or sharing personal items with an infected person. It can also be passed from mother to child. The University of Maryland Medical Center notes that most people with hepatitis C develop the chronic form of the disease, which may be symptomless until cirrhosis, or liver scarring, has developed. Doctors may treat chronic hepatitis C with a combination of interferon alpha and ribaviri.
Chronic Kidney Disease
Dark urine and weight loss can also be signs of chronic kidney disease. You may notice changes in urinary habits -- such as urinating less than usual -- and urine that looks foamy or bubbly. You may also experience edema, or swelling, of your legs, ankles, face, hands or feet, as well as fatigue, itchy skin, nausea, loss of appetite and an unpleasant, metallic or bitter taste in your mouth. Kidney disease can range from mild to severe and in some cases may require dialysis.