How Are Kidney Stones Diagnosed? Ultrasound, CT Scan and Urine Tests

Kidney stones can cause sudden pain in the back, side or lower abdomen. Some people also experience blood in the urine, nausea, vomiting or difficulty passing urine. However, these symptoms do not always confirm the presence of a kidney stone. Other urinary and abdominal conditions can cause similar problems.

Our doctors use a combination of medical history, physical examination, urine tests, blood tests and imaging investigations to diagnose kidney stones. Among these investigations, ultrasound and CT scans play important roles in identifying stones and checking whether they block urine flow.

Each test provides different information. A urine test can detect blood or signs of infection, while an ultrasound can identify many kidney stones and swelling. A CT scan can show the stone’s exact size, location and other details.

At Jyoti Hospital, Gurugram, our urology team evaluates kidney stones by considering your symptoms, medical history and investigation results. Understanding these diagnostic tests can help you prepare for your consultation and know what to expect.

How Do Doctors Diagnose Kidney Stones?

Our doctors do not rely on symptoms alone to diagnose kidney stones. They assess your condition and select suitable tests to confirm the diagnosis.

The diagnostic process generally includes:

1. Medical history: Our doctor asks about pain, urinary symptoms, previous stones and other health conditions.
2. Physical examination: Our doctor checks for tenderness and other signs that may indicate a kidney or urinary problem.
3. Urine tests: These tests look for blood, infection and other abnormalities.
4. Blood tests: These tests help assess kidney function and identify certain factors associated with stone formation.
5. Imaging tests: Ultrasound, CT scans or other imaging investigations help locate stones and assess urinary obstruction.

Our doctor do not need every test. The choice depends on your symptoms, medical history, clinical findings and the information that each investigation needs to provide.

What Are the First Signs That Doctors Look For?

Kidney stones can produce different symptoms depending on their size and location. Your doctor will ask about these symptoms before selecting diagnostic tests.

• Pain in the Back or Side
  • Kidney stone pain often starts below the ribs, on one side of the back or abdomen. The pain may become severe when a stone moves into the ureter or blocks urine flow.
• Pain That Spreads Towards the Groin
  • A stone moving through the ureter can cause pain that spreads from the side or back towards the lower abdomen and groin.
• Blood in Urine
  • A kidney stone can irritate the lining of the urinary tract and cause bleeding. You may notice pink, red or brown urine. A urine examination can also detect microscopic blood that you cannot see.
• Burning or Frequent Urination
  • A stone near the bladder may cause burning, frequent urination or a sudden urge to pass urine.
  • These symptoms can also indicate a urinary tract infection, so your doctor may recommend a urine culture.
• Nausea and Vomiting
  • Severe kidney stone pain can trigger nausea and vomiting. Some people also experience sweating and restlessness.
• Fever and Chills
  • Fever and chills may indicate an infection. If you have these symptoms along with suspected kidney stones, seek urgent medical attention because an infected, obstructed kidney requires prompt treatment.
• No Symptoms at All
  • Some kidney stones remain inside the kidney without causing pain or noticeable urinary symptoms.
  • Doctors may discover these silent stones during an ultrasound or CT scan performed for another medical reason.

What Questions Will Your Doctor Ask Before Diagnosing Kidney Stones?

Your medical history helps your doctor understand your symptoms and identify factors that increase your risk of kidney stones.

Our doctor will ask:

• When did the pain begin?
• Where do you feel the pain?
• Does the pain spread towards your abdomen or groin?
• Does the pain come and go, or does it remain constant?
• Have you noticed blood in your urine?
• Do you experience burning or frequent urination?
• Have you experienced fever, chills or vomiting?
• Have you had kidney stones before?
• Does anyone in your family have a history of kidney stones?
• How much water do you usually drink?
• Do you take any regular medicines or supplements?

Our doctor also ask about conditions such as diabetes, obesity, kidney disease and previous urinary infections.

These details help the doctor choose the right investigations and assess your risk of developing stones again.

How Are Kidney Stones Diagnosed With Ultrasound?

Ultrasound is one of the commonly used imaging tests for kidney stones. It uses high-frequency sound waves to create images of the kidneys and urinary tract.

The test does not use ionising radiation, which makes it particularly useful in situations where doctors want to avoid radiation exposure.

What Can an Ultrasound Detect?

An ultrasound may help your doctor identify:

• Kidney stones
• The approximate size and location of visible stones
• Multiple stones inside the kidney
• Swelling of the kidney
• Urinary obstruction
• Changes in the bladder
• Certain abnormalities in the urinary tract

One important finding is hydronephrosis, which means swelling of the kidney due to a build-up of urine. A stone blocking urine drainage can cause this condition.

How Does a Kidney Ultrasound Work?

The ultrasound examination usually follows these steps:

1. You lie on an examination table.
2. The healthcare professional applies gel to your abdomen or side.
3. They move a handheld ultrasound probe over the skin.
4. The probe sends sound waves into your body and captures the returning signals.
5. The machine converts these signals into images of your kidneys and urinary tract.

The examination usually takes a short time and does not require an incision or anaesthesia.

Our urology team ask you to drink water and arrive with a full bladder, particularly when they need to examine the bladder and lower urinary tract.

Can Ultrasound Detect Every Kidney Stone?

No. Ultrasound cannot detect every kidney stone.

Very small stones, certain ureteric stones and stones in difficult-to-image locations may not appear clearly.

Ultrasound can also show kidney swelling without directly identifying the stone causing the obstruction.

If our doctor suspects a kidney stone despite a normal or unclear ultrasound, they may recommend a CT scan.

When Do Doctors Prefer Ultrasound?

Our doctors often consider ultrasound:

• As an initial imaging test in suitable patients
• For monitoring known kidney stones
• During pregnancy
• In children
• When they want to avoid radiation exposure
• During follow-up of selected uncomplicated kidney stones

Ultrasound provides useful information, but our doctor may need additional imaging to confirm the diagnosis.

How Does a CT Scan Diagnose Kidney Stones?

A CT scan provides detailed cross-sectional images of the kidneys, ureters and bladder.

Our doctors commonly use a non-contrast CT scan, also called non-contrast computed tomography (NCCT), to diagnose suspected kidney stones.

This test helps identify stones that ultrasound may miss and provides detailed information about their size, location and number.

What Can a CT Scan Show?

A CT scan can help our doctor determine:

1. Stone size: The scan measures the stone and helps estimate whether it may pass naturally.
2. Stone location: It identifies whether the stone lies in the kidney, ureter or another part of the urinary tract.
3. Number of stones: It can identify multiple stones in the urinary tract.
4. Urinary obstruction: The scan can show whether a stone blocks urine drainage.
5. Stone density: CT measurements provide information that may help doctors plan treatment.
6. Other abdominal conditions: If the scan does not show a stone, it may help identify another possible cause of your pain.

How Does a CT Scan Work?

A CT scan usually follows these steps:

1. You lie on a movable examination table.
2. The technician positions you inside the CT scanner.
3. The scanner takes multiple X-ray images from different angles.
4. A computer combines these images to create detailed cross-sectional pictures.
5. A radiologist reviews the images and prepares a report.

The examination usually takes only a few minutes. You may need to remain still and briefly hold your breath during image capture.

Why Do Doctors Prefer a Non-Contrast CT Scan for Kidney Stones?

A non-contrast CT scan can detect most common kidney and ureteric stones without injecting contrast dye.

It provides detailed information about the stone’s size, location and density. It can also show signs of urinary obstruction.

Our doctors may use contrast-enhanced imaging for other clinical questions, but they generally choose non-contrast CT when they specifically need to identify suspected urinary stones.

Does a CT Scan Detect Stones Better Than Ultrasound?

Yes. CT scans generally detect kidney and ureteric stones more accurately than ultrasound.

However, our doctors do not automatically recommend CT scans for every patient. CT uses ionising radiation, so our doctor considers the benefits and potential risks before ordering it.

For suitable patients, our doctors use ultrasound first and reserve CT for unclear findings or situations that need more detailed imaging.

When Do Doctors Recommend a CT Scan?

Our doctor recommend a CT scan when:

• You experience severe or persistent pain.
• Ultrasound does not clearly identify the suspected stone.
• Your symptoms strongly suggest a kidney stone.
• Our doctor needs to determine the exact stone size and location.
• Our doctor suspects urinary obstruction or complications.
• You need detailed imaging before a planned procedure.

Our doctors also consider low-dose CT protocols when clinically appropriate to reduce radiation exposure.

What Is the Difference Between Ultrasound and CT Scan for Kidney Stones?

Both tests help diagnose kidney stones, but they provide different types of information.

Feature	Ultrasound	CT Scan
Imaging method	Sound waves	X-rays and computer-generated images
Radiation	No ionising radiation	Uses ionising radiation
Stone detection	Detects many kidney stones, but may miss small or ureteric stones	Generally detects stones more accurately
Stone measurement	Provides an approximate measurement	Provides detailed measurements
Stone location	Identifies many kidney stones and some ureteric stones	Shows the location of most common urinary stones
Urinary obstruction	Can show kidney swelling	Can show stones and signs of obstruction
Pregnancy	Often preferred for initial imaging	Doctors generally avoid it unless necessary
Follow-up	Useful for selected monitoring	Useful when detailed imaging is needed

Which test is better?

Neither test is automatically better for every patient. Ultrasound avoids radiation and works well in many situations. CT provides greater diagnostic detail and helps doctors identify stones that ultrasound may miss.

Our doctor chooses the investigation according to your symptoms and medical needs.

How Do Urine Tests Help Diagnose Kidney Stones?

Urine tests provide important information about bleeding, infection and substances associated with kidney stone formation.

However, a urine test alone cannot reliably confirm or rule out every kidney stone. Our doctors combine urine results with clinical findings and imaging.

1. Routine Urine Examination

A routine urine examination, also called urinalysis, checks the urine for several abnormalities.

It may identify:

• Red blood cells
• White blood cells
• Bacteria
• Crystals
• Protein
• Urine pH
• Other chemical abnormalities

2. Blood in Urine

A kidney stone can damage or irritate the urinary lining and cause bleeding.

A urine examination may detect red blood cells even when your urine looks normal.

However, blood in urine can also occur due to infections, kidney diseases, prostate conditions and other urinary tract problems.

3. Signs of Infection

White blood cells, nitrites and bacteria in the urine may indicate a urinary tract infection.

Our doctor recommend a urine culture to identify the bacteria and determine which antibiotics may work against them.

An infection alongside an obstructing kidney stone needs urgent medical attention.

4. Urine Crystals

Urine may contain crystals formed from minerals and other substances.

These findings can provide clues about the chemical environment that encourages stone formation. However, crystals do not necessarily mean that you have a kidney stone.

5. Urine pH

Urine pH measures how acidic or alkaline your urine is.

Certain types of stones form more easily under particular urine conditions. Our doctor use urine pH along with other test results to assess your stone risk.

What Is a Urine Culture, and Why Might You Need It?

A urine culture checks whether bacteria grow in a urine sample.

Our doctor may recommend this test if you experience burning during urination, fever, chills or other signs of infection.

The laboratory processes the sample to identify bacteria and may perform antibiotic sensitivity testing.

A urine culture becomes particularly important when our doctor suspects an infection alongside a kidney stone.

Remember: An infected kidney with urinary obstruction can become a medical emergency. Do not delay treatment while waiting for routine follow-up if you develop fever or chills with suspected obstruction.

Which Blood Tests Help Diagnose Kidney Stones?

Blood tests help our doctors assess kidney function, identify infection and look for metabolic factors that may contribute to stone formation.

Our doctor may recommend the following tests depending on your condition.

• Serum Creatinine: Creatinine is a waste product that the kidneys normally remove from the blood.
  • A blood creatinine test helps your doctor assess kidney function. An abnormal result may indicate reduced kidney function, although several conditions can affect creatinine levels.
• Blood Urea: This test provides additional information about kidney function and waste removal.
  • Our doctor interpret it alongside creatinine and other clinical findings.
• Serum Calcium: High calcium levels in the blood can contribute to certain types of kidney stones.
  • Our doctor check calcium levels when the medical history or stone findings suggest a possible calcium-related problem.
• Uric Acid: High uric acid levels can increase the risk of uric acid stones in some people.
  • Our doctor check blood uric acid as part of a broader evaluation.
• Complete Blood Count: A complete blood count (CBC) measures different types of blood cells.
  • Our doctor may use it to look for signs of infection or other abnormalities.
• Other Blood Tests: Depending on your condition, your doctor may check electrolytes and additional metabolic markers.

These tests help identify conditions that may affect kidney stone formation or treatment decisions.

What Is a 24-Hour Urine Test for Kidney Stones?

Some patients need a 24-hour urine test to identify factors that increase their risk of forming kidney stones.

This test does not usually serve as the first investigation for an acute episode of kidney stone pain. Our doctors mainly use it to evaluate stone formation and prevent recurrence.

During the test, you collect all urine passed over a 24-hour period in a special container.

The laboratory measures substances such as:

• Calcium
• Oxalate
• Uric acid
• Citrate
• Sodium
• Creatinine
• Total urine volume

The results help your doctor understand why you may be forming stones.

Our urologist recommend this test if you have recurrent stones, multiple stones or other risk factors for recurrence.

Can an X-Ray Detect Kidney Stones?

Yes. A plain abdominal X-ray, commonly called a KUB X-ray, can detect some kidney and urinary stones.

However, not all stones appear on a plain X-ray.

For example, uric acid stones generally do not show up clearly on standard X-ray images. Some other stones may also remain difficult to detect.

Our doctors may use a KUB X-ray to:

• Identify certain visible stones
• Monitor selected known stones
• Compare stone position during follow-up
• Assess changes after treatment

Our doctor may combine X-ray findings with ultrasound or CT results to obtain a more complete picture.

Which Test Is Best for Diagnosing Kidney Stones?

The best test depends on your symptoms, age, medical history and the clinical question your doctor needs to answer.

Situation	Test doctors may consider
Initial assessment in a suitable patient	Ultrasound
Suspected stone with unclear ultrasound findings	Non-contrast CT
Acute flank pain where detailed confirmation is needed	Non-contrast CT
Pregnancy	Ultrasound first
Child with suspected kidney stones	Ultrasound first
Blood or infection indicators	Urine examination and, when needed, urine culture
Assessment of kidney function	Blood tests
Recurrent stone formation	Stone analysis and metabolic evaluation
Follow-up of selected known stones	Ultrasound or other suitable imaging

The European Association of Urology recommends ultrasound as an initial imaging tool in many situations and non-contrast CT to confirm suspected stones in patients with acute flank pain after initial ultrasound assessment. Our doctor must still consider the individual clinical situation.

Can Kidney Stones Be Diagnosed Without a CT Scan?

Yes. Doctors can diagnose many kidney stones without a CT scan.

An ultrasound may identify the stone, show its approximate size and reveal swelling caused by urinary obstruction. Urine and blood tests can provide additional information.

However, ultrasound may miss small stones or stones located in certain parts of the ureter.

If our doctor needs more detailed information or the initial findings do not explain your symptoms, they may recommend a CT scan.

The decision depends on the need for diagnostic accuracy and the importance of limiting radiation exposure.

What Happens After Doctors Confirm Kidney Stones?

After diagnosing a kidney stone, your doctor assesses its size, location, number and effect on urine drainage. Our doctor may also review your kidney function and check for infection.

Based on these findings, our urologist may recommend:

• Observation: Small stones that do not cause complications may pass naturally or remain stable.
  • Our doctor may recommend regular imaging to monitor the stone.
• Medicines: Our doctor may prescribe pain-relief medicines or other medicines depending on the stone and your symptoms.
  • For selected ureteric stones, our doctor consider medicines that help stone passage.
• Extracorporeal Shock Wave Lithotripsy (ESWL): ESWL uses focused shock waves to break suitable stones into smaller fragments that can pass through the urine.
• Ureteroscopy (URS): During ureteroscopy, our urologist passes a thin instrument through the urinary passage to reach the stone. Our urologist may use a laser to break the stone and remove the fragments.
• Retrograde Intrarenal Surgery (RIRS): RIRS allows the urologist to reach stones inside the kidney using a flexible ureteroscope and break them with a laser.
• Percutaneous Nephrolithotomy (PCNL): Our doctors may recommend PCNL for large or complex kidney stones. Our urologist creates a small passage through the back to reach and remove the stone.

The right treatment depends on the diagnostic findings. A stone’s size alone does not determine the treatment plan.

When Should You Get Tested for Kidney Stones?

You should consult our urology team if you experience symptoms that may indicate kidney stones.

Arrange a medical evaluation if you notice:

• Pain in the side or back
• Pain spreading towards the lower abdomen or groin
• Blood in your urine
• Burning during urination
• Frequent or urgent urination
• Recurrent urinary infections
• Nausea or vomiting with suspected kidney stone pain
• A previous history of kidney stones with new symptoms

You should also discuss an incidental kidney stone found during an ultrasound or CT scan, even if you do not experience pain.

When Is Kidney Stone Diagnosis an Emergency?

Some symptoms require immediate medical assessment.

Visit our emergency department if you experience:

• Fever or chills with suspected kidney stones
• Severe or uncontrolled pain
• Persistent vomiting
• Inability to pass urine
• Very low urine output
• Severe weakness or dizziness

A kidney stone that blocks urine flow while an infection develops can become dangerous. Our doctors may need to drain the kidney urgently and treat the infection before removing the stone.

People with a single functioning kidney or suspected obstruction also need prompt medical assessment.

How Jyoti Hospital Can Help

Accurate diagnosis helps doctors choose the right treatment for kidney stones and reduce the risk of complications.

At Jyoti Hospital, Gurugram, our urology team evaluates kidney stone problems using clinical assessment and appropriate diagnostic investigations.

Our doctors review your symptoms, medical history and investigation reports before recommending observation or treatment.

The hospital’s urology services include endourology and stone procedures such as:

• Ureteroscopy (URS)
• Retrograde intrarenal surgery (RIRS)
• Percutaneous nephrolithotomy (PCNL)
• Mini-PCNL
• Extracorporeal shock wave lithotripsy (ESWL)

Our urologist can explain your investigation findings, discuss suitable treatment options and help you understand the next steps.

If you experience symptoms of kidney stones or have an imaging report that shows a stone, consult our urologist for an appropriate evaluation.

Final Thoughts

Our doctors diagnose kidney stones through a combination of medical history, physical examination, urine tests, blood tests and imaging investigations.

Ultrasound helps identify many kidney stones without exposing you to ionising radiation. A CT scan provides more detailed images and generally detects stones more accurately. Urine tests help identify blood, infection and other abnormalities, while blood tests assess kidney function and possible stone-forming factors.

No single test suits every patient. Our doctor selects investigations according to your symptoms, medical history and clinical needs.

If you suspect kidney stones, consult our urologist at Jyoti Hospital, Gurugram, for an appropriate diagnosis and treatment plan.

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FAQs

1. Which test is best for diagnosing kidney stones?
   • A non-contrast CT scan generally provides the most detailed and accurate imaging for suspected kidney stones. However, doctors often use ultrasound first in suitable patients, particularly children and pregnant women.
2. Can an ultrasound detect kidney stones?
   • Yes. Ultrasound can detect many kidney stones and identify swelling caused by urinary obstruction. However, it may miss very small stones or stones located in certain parts of the ureter.
3. Can a urine test confirm kidney stones?
   • A urine test alone cannot reliably confirm every kidney stone. It can detect blood, infection and crystals, which provide useful diagnostic information. Doctors usually combine urine results with imaging findings.
4. Which test detects kidney stones during pregnancy?
   • Doctors generally prefer ultrasound as the initial imaging test during pregnancy because it does not use ionising radiation. They consider additional imaging only when the clinical situation requires it.
5. Can kidney stones be present even if ultrasound is normal?
   • Yes. Ultrasound may miss small stones or stones in certain locations. If your symptoms strongly suggest a kidney stone, your doctor may recommend additional imaging, such as a CT scan.