You are right. Kidney problems can cause dark circles under eyes. Yet there are many causes to dark circles under eyes. The first simple reason of dark circle is poor sleeping. Take a good rest, then it can disappear. Age, lack of nutrition, pregnancy, eczema, heredity, blood circulation and so on. There are really too many reason lead to dark circles under eyes. If you are just lack of sleep, taking a good rest would be enough for you. If the dark circles are caused by the weight of glasses which made blood circulation bad around eyes, you can try contact lenses.
As to kidney problems, dark bags is an indication of your body, that there might be something wrong with your kidney, yet if you want to find out what exactly problem it is, I strongly suggest you to see the doctor and have a detailed check. You'd better do it as soon as possible if you do believe you have some problems with kidney.
It may be true, because some chronic kidney problems can cause dark circle. Dark circles links with the way blood is circulating through the thin tissue surrounding the eyes. It's more than just the circulation of the blood. Your only way to be is to see your GP and test some simple urine and blood.
Well, first, you should know that in most cases, people who have dark circles around the eyes have nothing wrong with kidney problem at all. However, there are also some chronic kidney problems can cause your dark circles under your eyes. In my opinion, you should go and see your GP and have some simple urine and blood tests done. So you can make sure if your symptom is caused by kidney problem or not. And also, stress, and bad life habits can lead to dark circles too. So you can have some Moisturizers containing Vitamin E and K, so that it can lessen the appearance of dark circles. Beside, you can eat some black chocolate which are rich in Lutein and zeaxanthin, which can do a good job to your dark circles and the sight. Also, many kinds of oil, such as the black seed oil are very effective to your dark circles too. Anyway, just have a try.