What does dark yellow urine mean?

Dehydration: Dark yellow urine is a result of dehydration. The kidneys are trying to retain more water. As long as it doesn't burn, all you would need to do is drink more water.

Blood or dehydration: Small amounts of blood, especially if coming from the kidney ann give urine a dark or smokey appearance. Insufficient fluid intake is probably most common cause of dark urine due to concentration. Try drinking 8-10 glasses of water or other low calorie beverages and see if urine clears. Suggest you get urine checked if it remains dark.