My husband went for an ultrasound scan a month ago and the technician said he had a blocked kidney. It looked dark on the image. She said he had probably had it sometime and that it was "proabably" stones that were causing the blockage. Of course I'm worried it might be cancer (he went becuase he had micoscopic amounts of blood in his urine). He has his follow up in 6 weeks time so maybe that's a sign that it's not an urgent problem? He is a cigar smoker (4 a day) and is 60