Hi and welcome to Healthcaremagic. Thank you for your query. I am Dr. Rommstein, I understand your concerns and I will try to help you as much as I can. Cyst sis possible cause only if this is large and malignant. otherwise, this is not likely to be it. This may be is caused by urinary infection including kidneys infection or urinary stones so you should do urine analysis, urinoculture and kidneys ultrasound to rule these out which are most common causes. You should drink raspberry tea and plenty of water till you do tests. You should reduce salt in your diet as well, alcohol and carbonated drinks. In most cases this is self limiting but sometimes antibiotics are required and more invasive tests such as cystoscopy or pyelography or CT scan. Less common causes include tumors, glomerulonephritis and metabolic diseases. I hope I have answered you query. If you have any further questions you can contact us in every time. Kindly regards. Wish you a good health.DR. Ivan Rommstein