I will suggest that a kidney function test ( serum urea, creatinine, BUN ), urinalysis, kidney ultrasound, 24 hours proteinuria and serum albumin
dosages should be done in order to identify any possibility of a kidney diseases ( could be kidney failure, kidney infection
, nephritic/nephrotic syndrome
etc). For a more detailed investigation a liver function test, and complete blood count
could be included to identify the possible causes of the dark circles
under the eyes.
So from this point, i'll simply suggest you see an internist (internal medicine specialist of this kind of affections) to further assist you on the diagnosis and proper management.
Hope this helps