Obstruction of the kidney occurs if the tube draining the kidney (the ureter becomes blocked. This may have many possible causes, which can be briefly rounded up in to 3 main groups:

• obstruction from within the tube, such as a stone
• obstruction from outside the tube, such as a tumour in a neighbouring organ
• obstruction arising in the wall of the tube, such as a muscular thickening

In practice, the underlying cause may be of secondary importance, and the primary consideration may well be to unblock the system. It is remarkable how variable the symptoms may be. Some people will get excruciating pain, similar to that experienced by mothers during childbirth, whist in other people the obstruction may be completely silent, and the patient may well be completely unaware that anything is amiss. Likewise, the damage done may be very variable - in itself, a kidney can withstand short periods of complete obstruction with very little damage, but gradually the kidney can become severely damaged. Many factors may determine the extent of the problem in any individual case.

Thus, if you have an obstructed kidney, the urologist will be keen to know for how long it is likely to have been obstructed, and what is causing the obstruction - the presence or absence of infection will also be a crucial factor. X rays, ultrasound examinations, CT scans, renograms and endoscopy may all have a role to play in determining the nature of the problem.

Obviously it is impossible to go in to the treatment that will be recommended, as this will be decided by the outcome of the investigations.