What is the Renal Cyst Size that can Cause Pain

Renal cyst is a common cystic disorder and it is the general term for all cystic masses formed in the kidneys. There are many types of cystic diseases, for example the common ones include simple kidney cyst, parapelvic cyst, PKD, etc. With the popularization of physical examination and widely use of B ultrasound and CT, there has been great increase in the detection rate and it has become a common kidney disease in clinic.

Renal cyst is a chronically progressive disease and its prognosis is relatively good. In the early stage the cyst is small in size and in some cases the cysts may even smaller than 1cm and it is often found by accident in B ultrasound or CT scan done for other illness conditions. If there is no symptom due to oppression and obstruction, it will not affect patients’ normal life and they need not to have treatment or medicines except regular B ultrasound every 6 to 12 months.

However as the cyst grow large and begin to oppress surrounding renal intrinsic cells and tissues, there will be symptoms and discomforts. One of the most common symptoms and signs is pains in back, sides and upper abdomen. As for what is the general renal cyst size that can cause pain, there are slight individual differences, but cysts that are larger than 3cm will begin to cause back pains and other discomforts.

There are many factors in daily life that can stimulate the cysts to grow and the cysts will experience rapid growth and enlargement if patients do not know they have the disease or if do not pay enough attention and cares. The enlarged cysts will oppress surrounding tissues and stretch the renal capsule. What is more, large size cyst will enlarge the kidney and cause kidney to fall. In this case the pain is persistent but dull. The pain can sometimes be sharp and unbearable and it might due to stones in the kidneys or cyst rupture. Kidney stone is one common complication of renal cysts. If the stones remain in the kidneys, there can be no pain; however if the stone passes from kidney to the bladder and out of the body, it will cause sharp pain which is like cutting with knife and sometimes even blood in urine.