6.3.3 Hydronephrosis
Hydronephrosis is a condition in which one or both kidneys become swollen due to incomplete emptying of the urinary tract.Hydronephrosis can occur in people of all ages.In children，it is often due to structural changes in the body（anatomic abnormalities）present since birth or before.The primary cause of obstruction in adults is kidney stones（renal calculi）.The patient with hydronephrosis may complain of intense flank pain，nausea，vomiting，scanty or no urine output（oliguria or anuria），and the presence of blood in the urine（hematuria）.
An ultrasound is typically used to confirm a diagnosis.This procedure uses sound waves to create an image of your kidneys.A doctor can also confirm a diagnosis with xrays，computerized tomography（CT）and magnetic resonance imaging（MRI）.Diagnosis could also involve a cystoscopy，which uses a long tube with a light and camera at the end（cytoscope）that allows the doctor to look inside the bladder and urethra.Blood and urine tests can also check kidney function.
Hydronephrosis is usually treated by addressing the underlying disease or cause，such as a kidney stone or infection.A kidney stone can pass through by itself or might be severe enough to require removal with surgery.In cases of severe blockage and hydronephrosis，excess urine may need to be removed using either a catheter to drain urine from the bladder or a special tube called a nephrostomy that drains urine from the kidney.Severe cases of urinary blockage and hydronephrosis can damage the kidneys and lead to kidney failure.However，most people can recover from hydronephrosis if treated promptly.
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Task 5 Fill in the blanks with proper words.
1.________is the swelling of a kidney due to a build-up of urine.
2.The primary cause of obstruction or a blockage from the kidney to the bladder in adults is________.
3.During a（n）________，a urinary tract specialist uses a cystoscope to view the inside of the bladder.(https://www.daowen.com)
4.A special tube called a（n）________might be used to drain urine from the kidney.
5.________is the presence of red blood cells in the urine.
6.Patients with hydronephrosis may complain of________or anuria，which means“scanty or no urine output”.
7.A（n）________is typically used to confirm a diagnosis of swollen kidneys.
8.Excess urine may need to be removed in case of severe________or hydronephrosis.
9.________is a procedure performed to withdraw urine from kidney by creating an artificial opening between the kidney and the skin.
10.Severe cases of hydronephrosis without proper treatment may lead to________.