Hydronephrosis – Causes, Symptoms & Treatment


Hydronephrosis represents a pathological enlargement of the renal pelvis and the renal calyx system. It is also referred to as a water sac kidney and is caused by chronic urinary stasis . In the long term, the increase in pressure in the renal cavities can lead to destruction of the kidney tissue.

What is hydronephrosis?

Hydronephrosis is a “sack-like” expansion (dilatation) of the urine collection basin or renal cavity system. The disease is the result of an obstruction in the flow of urine with the resulting impairment or destruction of the kidney tissue. Therefore, it is also referred to as urinary stasis kidney or water sac kidney.

The problem lies in a lack of drainage of the urine, which results in a progressive expansion of the kidneys . Depending on the location, there is not only a sac-like expansion of the renal cavity system, but also the ureters. Hydronephrosis is therefore the result of excess urinary pressure. Both kidneys are affected in only about 10% of cases. As the disease progresses, there is a significant reduction in kidney function.

If hydronephrosis becomes chronic, permanent damage to the renal parenchyma can occur, ie a loss of function of the renal tissue. Reduced filter performance and, in the worst case, kidney failure can be the long-term consequences. Hydronephrosis does not necessarily have to be accompanied by symptoms immediately, possible first signs can be flank, back or abdominal pain, but also dizziness, vomiting or cramps.


There are a variety of causes of urinary obstruction. They are classified according to the localization of their occurrence; it is also important whether they are outside or inside the urine collection basin. The most common reasons include mechanical constrictions, eg due to kidney stones in the urinary system.

This leads to narrowing of the ureters and urinary retention. This outflow obstruction leads, for example, to stenosis of the renal pelvis. The group of mechanical causes of hydronephrosis also includes bladder cancer , bladder stones or a narrowing of the bladder neck. Causes located outside the urinary system can be tumors that constrict the ureters and thus impair the flow of urine, such as prostate or uterine cancer .

Other triggers of hydronephrosis can be malformations that lead to a reflux of urine into the kidneys: With this so-called vesicouretero-renal reflux , the ureter does not close after urination (no longer properly) and reflux occurs.

More rarely, the urinary stasis kidney is also caused by neuromuscular diseases and the resulting bladder emptying disorders. This can occur with multiple sclerosis , tetraplegia or other neurogenic diseases (especially paralysis). In rare cases, drug abuse can also be causally related to hydronephrosis.

Typical Symptoms & Signs

Diagnosis & History

Hydronephrosis does not have to lead directly to concise symptoms. An acute urinary stasis kidney can cause symptoms similar to renal colic : severe, colicky pain in the flank, abdomen and back area, possibly associated with cramps.

Blood in the urine is also a possible symptom in the acute course of the disease. The chronic development of hydronephrosis occurs rather insidiously – here the symptoms can also be accompanied by pain, but also be similar to kidney failure : dizziness, nausea, vomiting, weakness, muscle spasms and local pressure as well as disorders in the digestive tract are possible.

Sonography of the abdomen, the urinary tract and the bladder is necessary as an imaging procedure . This also allows the extent of hydronephrosis to be estimated. Computed tomography of the abdomen as well as urethroscopy , as well as angiography and excretory urography, are possible for further clarification of the cause .

Laboratory tests can not only measure blood in the urine, the creatinine value is also crucial; it provides information about the filter performance of the kidneys, among other things. If hydronephrosis remains undetected for a long time and the disease progresses, the long-term consequences are high blood pressure (hypertension) and renal insufficiency as well as permanent damage to the kidneys.


Over the long term, hydronephrosis can severely and irreversibly damage the tissue around the kidneys. The person affected primarily suffers from various types of pain, which, however, occur in the area of ​​the kidneys and the back. In most cases, this pain spreads to other parts of the body.The muscles spasm and epileptic seizures can occur. The patients also complain of vomiting and dizziness. It is not uncommon for these symptoms to lead to a panic attack or sweating. Due to the constant pain, many patients are irritated and can no longer enjoy everyday life.

They withdraw from active life and the patient’s resilience drops significantly. Digestive disorders can also occur. In the worst case, the person affected suffers from kidney failure, so that he is dependent on a donor kidney or on dialysis. If left untreated, the patient dies from renal failure.

The treatment does not lead to any further complications. However, its success depends heavily on the severity of the hydronephrosis and does not always lead to a positive course of the disease. Life expectancy can also be reduced by hydronephrosis.

When should you go to the doctor?

If symptoms such as abdominal pain or muscle cramps are noticed, hydronephrosis may be present. A doctor’s visit is indicated if the signs of illness increase or have not subsided after three to four days at the latest. If other symptoms appear, a doctor must be consulted. In particular, intense back pain and nausea and vomiting are clear warning signs that need to be investigated. If it is actually a urinary stasis kidney, immediate treatment is necessary.

Patients who notice blood in their urine or have trouble urinating should speak to their GP . This applies in particular if another illness is already present. Typical causes of hydronephrosis are kidney stones, bladder stones or bladder cancer. Malformations or neuromuscular diseases can also trigger hydronephrosis. If one of these conditions is present, you must go to the doctor with unusual symptoms on the same day. The initial examination can be carried out by the general practitioner. A urologist or a nephrologist should then be consulted, depending on the type and severity of the symptoms. If you have severe symptoms, you should go to the hospital.

Treatment & Therapy

The therapy of hydronephrosis is inevitably dependent on the respective cause. The most important goal is, of course, to permanently restore the flow of urine from the kidneys to the bladder and, in acute cases, to effectively treat the patient’s pain.

In the case of a mechanical cause of the urinary stasis kidney, the elimination of the flow obstruction is the first priority. This can be done by endoscopic or surgical removal. In any case, it is important to prevent infections in the urinary system. In the case of kidney stones as the cause of the water sac kidney, not only pain therapy is carried out , but measures are also taken to remove the kidney stones from the urinary system.

If these cannot be excreted naturally, the kidney stones are broken up in the urinary system using shock waves . If this is not possible, there are alternative methods of renal pelvic plastic surgery to choose from. Depending on the progress of the hydronephrosis, the urinary tract can be surgically relocated (recanalization).

The treating doctor has several options here: A stent (vascular prosthesis) can be implanted and, similar to a bypass, a “new” ureter can be placed. Or he decides to surgically relocate the ureter intraperitoneally, ie within the abdomen. If these options cannot be implemented, the installation of an artificial bladder outlet (urostoma) can also be a therapeutic alternative.

All of these measures are aimed at restoring and permanently guaranteeing the essential urinary outflow and the excretion of urinary substances to a sufficient extent. If the therapeutic measures mentioned are no longer possible and the course of the disease or the damage to the kidneys has progressed too far, it may also be necessary to remove the kidneys.

Outlook & Forecast

The prognosis of hydronephrosis depends on its cause and prompt treatment. If the therapy is successful within a few days or weeks, the kidney tissue can fully recover. No kidney damage remains.

Without treatment, however, kidney failure can occur, which is no longer completely curable. In very severe cases there is even a risk of total loss of kidney function. However, hydronephrosis is not that rare. Newborns and infants often develop it as a result of congenital disorders. It often occurs in pregnant women when the uterus puts pressure on the urethra, and in men it occurs due to diseases of the prostate. Therefore, in addition to pregnant women, older men are usually affected.

In contrast to men, the prognosis for hydronephrosis is usually very good for women. In almost all women, the kidneys return to normal after pregnancy without any treatment. Very often, the disease is not even noticed at first because the kidneys expand only slowly. However, high blood pressure rarely develops as part of hydronephrosis . In some cases, the loss of urine production and, as already mentioned, damage to the kidneys is also possible. Treatment for hydronephrosis depends on the cause. If the urinary obstruction is eliminated quickly, there is usually no risk of consequential damage.


Since hydronephrosis can have a very wide range of causes, immediate prevention is very difficult. In any case, the general health of the kidneys and bladder can be influenced by paying attention to an adequate water intake – from childhood to old age.

In this context, the consumption of alcohol in only small amounts is to be regarded as just as beneficial. A healthy lifestyle and sufficient consumption of water are certainly the best preventive measures with regard to this disease.


In the case of hydronephrosis, the measures or the options for aftercare are very limited or not available at all in most cases. The affected person is primarily dependent on early detection and treatment of the disease so that further complications can be prevented. This also prevents the symptoms from getting worse.

In the worst case, however, hydronephrosis can lead to complete destruction of the kidneys, which can also lead to the death of the person concerned. The treatment itself is always based on the exact cause of this disease, so that no general prediction can be given. In some cases, medication can also be taken to relieve the symptoms.

It is important to ensure that it is taken regularly and that the dosage is correct. If anything is unclear or you have any questions, you should first consult a doctor. If you have any questions about side effects or interactions with other medicines, you should always consult a doctor first. In some cases, hydronephrosis also makes sense for psychological treatment. Contact with other people affected by the disease can also be useful, as this can lead to an exchange of information.

You can do that yourself

Hydronehphrosis requires immediate medical examination or care. If the causative kidney congestion is not very advanced, alternative means can be used to relieve the symptoms and release the congestion.

One effective household remedy is apple cider vinegar . Mixed with acacia honey and mineral water, it dissolves kidney stones and can prevent hydronephrosis. Homeopathy offers the remedy “Berberis vulgaris”, which is used in various diseases of the excretory organs. Matricaria chamomilla or real chamomile also help with kidney pain. Urinary stones can be treated with Lycopodium. In addition, there are Schuessler salts , especially sodium phosphoricum and lithium chloratum. The use of homeopathic remedies should first be discussed with a doctor.

If hydronephrosis has already formed, medical treatment is required. The patient can support the pain therapy or treatment using shock waves by taking it easy and not putting any further strain on the kidneys. The responsible physician will answer the exact measures to be taken. In general, among other things, a healthy and balanced diet , adequate fluid intake and light physical activity are recommended.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.