A swollen kidney, medically called hydronephrosis, occurs when urine cannot drain normally from the kidney, causing the kidney to enlarge or swell. The swelling may affect one kidney or both kidneys, and the symptoms can range from mild discomfort to severe pain depending on the underlying cause.

Kidney swelling is not a disease by itself. It is usually a sign that something is interfering with urine flow, such as a kidney stone, urinary obstruction, infection or another urinary tract problem.

Recognizing swollen kidney symptoms early is important because prolonged obstruction can affect kidney function and, in some cases, lead to permanent kidney damage.

At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke, super specialist nephrologist and transplant physician, provides expert evaluation and treatment for hydronephrosis, kidney stones and kidney function disorders.

What is a swollen kidney?

A swollen kidney develops when urine accumulates inside the kidney because it cannot drain properly into the bladder.

This can happen because of:

• Kidney stones
• Ureteral obstruction
• Urinary tract narrowing
• Enlarged prostate
• Congenital urinary abnormalities
• Pregnancy related urinary compression
• Tumors or masses affecting urine flow

The severity may be mild, moderate or severe.

Common swollen kidney symptoms

The symptoms depend on how quickly the obstruction develops and how severe it is.

Common symptoms include:

• Flank pain
• Back pain
• Pain below the ribs
• Lower abdominal discomfort
• Nausea
• Vomiting
• Fever
• Burning during urination
• Frequent urination
• Blood in the urine
• Reduced urine output
• Swelling in severe kidney dysfunction

Some patients have no symptoms, especially when the swelling develops gradually.

Flank pain

The most common symptom of a swollen kidney is flank pain, which is usually felt on the side of the affected kidney.

The pain may be:

• Dull
• Aching
• Sharp
• Severe
• Intermittent
• Constant

Pain caused by kidney stones is often sudden and intense.

Pain in the back or side

Kidney swelling may cause pain in the:

• Upper lower back
• Side of the abdomen
• Area below the ribs

The pain may occur on the right side, left side or both sides depending on which kidney is affected.

Nausea and vomiting

Severe urinary obstruction can cause:

• Nausea
• Vomiting
• Sweating
• Restlessness

These symptoms commonly occur with acute kidney stone obstruction.

Fever and chills

Fever with kidney swelling is particularly important because it may indicate an infected obstructed kidney, which can become a medical emergency.

Seek immediate medical attention if kidney pain is accompanied by fever or chills.

Blood in the urine

A swollen kidney caused by a stone or urinary tract injury may produce blood in the urine.

The urine may appear:

• Pink
• Red
• Brown
• Tea colored

Microscopic blood may be detected only on urine testing.

Changes in urination

Kidney swelling may affect urination.

Possible symptoms include:

• Frequent urination
• Urgent urination
• Burning urination
• Difficulty passing urine
• Reduced urine output
• Intermittent urine flow

The exact pattern depends on the underlying cause.

Reduced urine output

Severe obstruction affecting one or both kidneys can reduce urine production.

A significant decrease in urine output requires urgent medical evaluation.

What causes a swollen kidney?

Kidney stones

A stone blocking the ureter is one of the most common causes of hydronephrosis.

Ureteral obstruction

Narrowing, scarring or compression of the ureter can interfere with urine drainage.

Enlarged prostate

In men, prostate enlargement can contribute to urinary obstruction.

Pregnancy

Temporary hydronephrosis may occur during pregnancy because of pressure on the urinary tract.

Congenital abnormalities

Some people are born with urinary tract structural problems that affect drainage.

Tumors

Masses affecting the kidney, ureter or surrounding structures may obstruct urine flow.

Blood clots

In some cases, blood clots within the urinary tract can cause obstruction.

Can a swollen kidney occur without pain?

Yes.

Gradual hydronephrosis may produce little or no pain.

Some patients are diagnosed incidentally during an ultrasound performed for another reason.

Even painless hydronephrosis may require evaluation because it can sometimes affect kidney function.

How is a swollen kidney diagnosed?

Diagnosis usually involves imaging studies.

Ultrasound

Ultrasound is commonly used to detect hydronephrosis and assess kidney swelling.

CT scan

CT imaging can help identify:

• Kidney stones
• Ureteral obstruction
• Tumors
• Structural abnormalities
• The severity of obstruction

Blood tests

Blood investigations may evaluate:

• Kidney function
• Infection
• Electrolytes

Urine tests

Urine examination may detect:

• Blood
• Infection
• Protein
• Other abnormalities

Can a swollen kidney damage the kidney?

Yes.

Prolonged obstruction can reduce kidney function and may eventually cause permanent kidney damage.

The risk depends on:

• Severity of obstruction
• Duration
• Whether one or both kidneys are affected
• Presence of infection
• Baseline kidney function

Early diagnosis and treatment are important.

Swollen kidney symptoms caused by kidney stones

When a kidney stone causes hydronephrosis, symptoms may include:

• Severe flank pain
• Pain radiating toward the groin
• Nausea
• Vomiting
• Blood in the urine
• Urinary urgency
• Difficulty passing urine

Stone related obstruction is a common reason for emergency kidney pain.

Swollen kidney symptoms caused by infection

An infected swollen kidney may cause:

• Fever
• Chills
• Flank pain
• Burning urination
• Frequent urination
• Nausea
• Weakness

This situation requires prompt medical treatment.

Treatment for a swollen kidney

Treatment focuses on the underlying cause of the obstruction.

Kidney stone treatment

Depending on the stone, treatment may involve:

• Medical therapy
• Ureteroscopy
• Laser lithotripsy
• Shock wave lithotripsy
• RIRS
• PCNL

Relief of obstruction

Significant obstruction may require:

• Ureteral stent placement
• Percutaneous nephrostomy
• Treatment of ureteral narrowing
• Management of prostate obstruction
• Other surgical or endoscopic procedures

Infection treatment

If infection is present, appropriate antibiotics and, in some cases, urgent drainage may be necessary.

Can a swollen kidney heal on its own?

Some mild cases may improve, particularly if a small stone passes naturally or temporary obstruction resolves.

However, persistent kidney swelling should never be assumed to be harmless.

Medical follow-up is important to confirm resolution and assess kidney function.

Can home remedies reduce kidney swelling?

Home remedies cannot reliably relieve hydronephrosis caused by significant obstruction.

Drinking excessive amounts of water does not necessarily solve urinary blockage and may delay appropriate treatment.

Persistent kidney swelling requires medical evaluation.

When should you seek emergency medical care?

Seek immediate medical attention if swollen kidney symptoms occur with:

• Fever
• Chills
• Severe flank pain
• Persistent vomiting
• Inability to pass urine
• Very little urine
• Significant blood in the urine
• Confusion
• Severe weakness
• Pregnancy with severe kidney pain

An infected obstructed kidney can become a serious medical emergency.

Swollen kidney evaluation at Prabhakar Bhurke Clinic

At Prabhakar Bhurke Clinic, Dr. Sandip Prabhakar Bhurke provides specialist evaluation for patients with swollen kidney symptoms and hydronephrosis.

Assessment may include:

• Kidney function testing
• Urine examination
• Ultrasound review
• CT scan interpretation
• Kidney stone evaluation
• Hydronephrosis assessment
• Obstruction evaluation
• Infection assessment
• Long-term kidney function monitoring

Treatment is individualized according to the cause of kidney swelling, obstruction severity and overall kidney health.

Frequently Asked Questions

What are the first symptoms of a swollen kidney?

Flank pain, back pain, nausea, urinary changes and sometimes blood in the urine are common early symptoms.

Can a swollen kidney occur without pain?

Yes. Some cases of hydronephrosis are discovered incidentally on imaging and may cause little or no pain.

Is a swollen kidney dangerous?

It can be. Persistent obstruction may affect kidney function, especially if infection is present.

Can kidney stones cause a swollen kidney?

Yes. A stone blocking the ureter is one of the most common causes of hydronephrosis.

Does a swollen kidney always require surgery?

No. Treatment depends on the underlying cause. Some cases require observation, while others need procedures to relieve obstruction.

Conclusion

Swollen kidney symptoms can range from mild flank discomfort to severe pain, fever and urinary obstruction. Hydronephrosis is often caused by kidney stones, urinary tract obstruction or infection, and early diagnosis is important to protect kidney function.

Persistent flank pain, fever, blood in the urine or reduced urine output should not be ignored.

For expert evaluation and personalized treatment of hydronephrosis, kidney stones and kidney function disorders, patients can consult Dr. Sandip Prabhakar Bhurke at Prabhakar Bhurke Clinic.

Medical Disclaimer

This article is intended for general educational purposes only and does not constitute medical advice, diagnosis or treatment. Swollen kidney symptoms can be caused by urinary obstruction, kidney stones, infection and other kidney disorders that may require urgent medical treatment. Do not rely solely on home remedies if you have severe flank pain, fever, vomiting, blood in the urine, difficulty passing urine or reduced urine output. Prompt medical evaluation is important because untreated hydronephrosis can affect kidney function. For personalized diagnosis and treatment, consult Dr. Sandip Prabhakar Bhurke or another qualified nephrologist.