Dark urine could be a sign of a number of health problems, but the most common ones are kidney or bladder problems. If you're experiencing dark urine, it's important to see a doctor to rule out any underlying health issue. Other potential causes of dark urine include: drinking too much coffee, drinking alcohol, being pregnant, taking medications that affect your kidneys or bladder, eating a high-sodium diet, and being diabetic. If you think you may have any of these diseases, it's important to talk to your doctor about your symptoms.