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Kidney Stone Tests & Reports | CT KUB, Urine & Blood Tests

Written By Dr. Vijayant Govinda Gupta
11 min read
03 Sep 2026
Kidney Stone Tests & Reports: CT KUB, Urine & Blood Tests

Why Are Tests Important For Kidney Stones?

Kidney stone treatment should not be decided only on the basis of pain. Two patients can have similar symptoms but very different stone size, location, kidney swelling, infection or urinary blockage.

Tests help the urologist confirm whether a stone is present, find its exact location, measure its size, assess whether urine flow is blocked and check whether the kidney or urinary tract is affected by infection.

Reports also help decide whether the patient needs observation, medicines, ESWL, URS, RIRS, PCNL or another treatment.

Important: Not every patient requires every test listed on this page. The investigations required depend on symptoms, age, previous stone history, infection, pregnancy, kidney function and whether surgery is being planned.

Important Tests For Kidney Stones

The following are some of the most commonly used investigations during kidney stone evaluation.

CT KUB Shows stone size, number, exact location, density, obstruction and surrounding urinary anatomy.
Ultrasound KUB Checks kidneys, urinary tract, hydronephrosis and many kidney stones without radiation exposure.
Urine Routine & Microscopy Can identify blood, white cells, crystals, urine pH and signs suggesting urinary infection.
Urine Culture Used when urinary infection is suspected and is especially important when an intervention is being planned.
Serum Creatinine / Kidney Function Helps assess whether kidney function is normal or affected by obstruction or another kidney problem.
Blood Calcium & Uric Acid May help identify metabolic factors associated with recurrent kidney stone formation.
Stone Analysis If a stone or fragment is available, analysis may help identify its composition and guide prevention.
24-Hour Urine Test Usually considered more selectively in recurrent or high-risk stone-forming patients.

Imaging Tests For Kidney Stones

1. CT KUB / Non-Contrast CT

A non-contrast CT scan of the kidneys, ureters and bladder is one of the most detailed tests used to evaluate urinary stones. It can show the exact stone location, size, number and whether the stone is causing blockage.

CT can also provide information about stone density, often expressed as Hounsfield Units or HU. Stone density, location and size can influence treatment planning, including whether ESWL or an endoscopic procedure may be more suitable.

A CT report may mention: stone size in millimetres, right or left side, kidney or ureter location, density, hydronephrosis, hydroureter, number of stones and other urinary tract findings.

2. Ultrasound KUB

Ultrasound uses sound waves rather than radiation. It is useful for checking kidney stones, kidney swelling or hydronephrosis, bladder findings and urinary tract dilatation.

Ultrasound can be particularly useful when avoiding radiation is important. In pregnancy, ultrasound is generally preferred over CT as the first imaging test. It is also commonly used first in children.

3. X-Ray KUB

Some calcium-containing stones can be visible on a plain X-ray KUB. However, not every type of kidney stone is visible on X-ray.

X-ray may sometimes be used for follow-up of a known radiopaque stone or around certain treatment pathways, but it does not provide the same information as CT.

4. Contrast CT Or Other Imaging

A contrast study is not required for every uncomplicated kidney stone. It may be advised in selected cases when the urologist needs additional information about urinary anatomy, kidney drainage, another suspected condition or before a planned procedure.

Which Urine Tests Are Needed For Kidney Stones?

Urine Routine Examination

A urine routine test is one of the basic investigations used in kidney stone patients. It may show red blood cells, white blood cells, crystals, protein, urine pH and other findings.

Blood in urine can occur with a urinary stone, while increased white blood cells, nitrites or bacteria may raise concern about urinary infection.

Urine Microscopy

Microscopy can help identify red cells, pus cells, crystals and other sediment present in the urine. Certain crystal patterns may provide clues about the type of stone, although stone composition cannot always be confirmed from urine microscopy alone.

Urine Culture

Urine culture checks whether bacteria are growing in the urine and, when positive, which antibiotics may be effective.

This becomes particularly important if the patient has fever, chills, burning urination, pus cells in urine, a history of urinary infection or is being prepared for an endoscopic or kidney stone procedure.

Fever with an obstructing kidney stone can be urgent. A patient with stone pain plus fever, chills, severe weakness or difficulty passing urine should seek medical evaluation rather than waiting only for routine follow-up.

Blood Tests For Kidney Stones

Serum Creatinine

Creatinine helps assess kidney function. This becomes especially important when there is obstruction, hydronephrosis, a solitary kidney or bilateral stones.

CBC / Complete Blood Count

A CBC may be advised to look for anaemia, elevated white blood cells or other findings, especially when infection or surgery is being considered.

Serum Calcium

Blood calcium may be checked because abnormal calcium levels can be associated with some recurrent calcium stone disorders.

Serum Uric Acid

Uric acid testing can be useful when evaluating uric acid stones or recurrent stone formation.

Electrolytes

Sodium, potassium and other electrolytes may be checked depending on kidney function, medical condition and planned treatment.

Other Metabolic Tests

Additional tests such as parathyroid hormone may be considered when blood calcium is high or when a specific metabolic problem is suspected.

24-Hour Urine Test & Stone Analysis

A first episode of kidney stone does not always mean that every patient needs a detailed metabolic work-up. More extensive testing is commonly considered in patients with recurrent stones, multiple stones, a strong family history or other high-risk features.

What Does A 24-Hour Urine Test Check?

Depending on the clinical situation, a 24-hour urine collection may measure urine volume, calcium, oxalate, uric acid, citrate, sodium, creatinine and urine pH.

These results can help identify why a patient forms stones repeatedly and allow diet or medical prevention to be more individualised.

Why Is Stone Analysis Useful?

If you naturally pass a stone or a stone fragment is removed during treatment, keep it if your doctor advises you to do so. Laboratory stone analysis can identify the mineral composition of the stone.

Common stone types include calcium oxalate, calcium phosphate, uric acid, infection-related stones and less common stones such as cystine.

Prevention becomes more accurate when the stone type is known. For example, prevention advice for a calcium oxalate stone may differ from the plan used for a uric acid stone.

Tests Before Kidney Stone Surgery

If ESWL, URS, RIRS, PCNL or another procedure is planned, the hospital may ask for additional investigations to confirm that treatment and anaesthesia can be performed safely.

Urine Culture

Used to identify urinary infection before a procedure. An active infection may need treatment before definitive stone surgery in many cases.

CBC & Kidney Function

Helps assess haemoglobin, infection markers and kidney function before treatment.

Blood Sugar

Blood glucose testing may be requested as part of pre-operative evaluation, particularly in patients with diabetes or when anaesthesia is planned.

Coagulation Profile

Bleeding and clotting tests may be required before selected procedures, especially when bleeding risk or blood-thinning medication needs assessment.

ECG / Anaesthesia Evaluation

Additional pre-anaesthesia testing can depend on age, medical history, heart or lung disease and the planned procedure.

Updated Imaging

The surgeon may require recent CT or ultrasound imaging if older reports no longer reflect the current stone position or condition.

Do not stop aspirin, blood thinners or other prescribed medicines yourself. The treating surgeon and anaesthesia team should advise which medicines need adjustment before surgery.

What Should You Check In A Kidney Stone Report?

A kidney stone report contains more useful information than only the words “stone present.” The following findings can directly affect treatment planning.

Stone Size

Stone size is usually written in millimetres. The chance of natural passage and the treatment options can change as stone size increases.

Stone Location

The report should identify whether the stone is in the kidney, renal pelvis, upper ureter, middle ureter or lower ureter. Location can influence whether observation, ESWL, URS, RIRS or PCNL is considered.

Number Of Stones

Some patients have a single stone while others have multiple stones in one or both kidneys. The total stone burden can change treatment planning.

Stone Density / Hounsfield Units

On CT, stone density may be described in Hounsfield Units. It can provide information about stone characteristics and may be useful when considering the expected response to shockwave treatment.

Hydronephrosis

Hydronephrosis means the kidney collecting system is swollen, usually because urine drainage is obstructed or impaired. The degree of swelling, symptoms and kidney function all need to be considered together.

Ureter Dilatation

Hydroureter or ureteric dilatation can occur when a ureter stone blocks urine flow. The report may describe the level of obstruction and the stone responsible.

Which Reports Should You Send Before Visiting?

If you already have investigations, sending them before your consultation can help the urology team understand your case. If you do not have reports yet, the required evaluation and tests can also be arranged after consultation.

CT KUB Report & Images Send the written report and, if available, the CT images or scan link/CD.
Ultrasound KUB Especially useful if CT has not yet been performed or for follow-up imaging.
Urine Routine Recent urine routine and microscopy report if available.
Urine Culture Send culture results if you have fever, recurrent UTI or have already been treated for infection.
Blood Tests Creatinine, CBC and other recent kidney or metabolic blood tests if already performed.
Previous Surgery Records Previous RIRS, URS, PCNL, ESWL or other stone treatment records can be important.
DJ Stent Information Tell the doctor if a DJ stent is currently present and when it was inserted.
Current Medicines Include blood thinners, diabetes medicines, antibiotics and other regular medication.
No reports yet? You can still visit the hospital. After evaluation, the urologist can advise which imaging, urine or blood tests are actually required for your case.

Kidney Stone Test & Report Videos

Watch these patient-education videos to understand kidney stone reports, warning signs and how reports help select the right procedure.

How To Read Kidney Stone Reports

PCNL vs RIRS vs Ureteroscopy

Warning Signs Of Kidney Stones

How Kidney Stone Reports Help Decide Treatment

The procedure should be selected after combining symptoms, CT or ultrasound findings, urine tests, kidney function and the overall medical condition of the patient.

ESWL

Shockwave treatment may be considered for selected stones. Stone size, location and density can affect the expected response.

URS / URSL

Ureteroscopy is commonly used for selected ureter stones, particularly when intervention is required because of pain, obstruction or failure to pass.

RIRS

RIRS uses a flexible scope and laser through the natural urinary passage to treat suitable kidney stones.

PCNL / Mini-PCNL

PCNL is commonly considered for larger, complex or high stone-burden kidney stones where direct access and stone removal may be advantageous.

Related Kidney Stone Treatment Pages

Kidney Stone Treatment In Delhi Complete guide to diagnosis, medicines, laser surgery and treatment planning. PCNL Surgery Cost In Delhi Fixed PCNL treatment information for large and complex kidney stones. RIRS Surgery Cost In Delhi Flexible laser treatment information for suitable kidney stones. URS Surgery Cost In Delhi Ureteroscopy and laser treatment for suitable ureter stones. ESWL Treatment Cost In Delhi Non-invasive shockwave treatment information and cost.

FAQs About Kidney Stone Tests & Reports

Which Test Is Best For Kidney Stones?
CT KUB is one of the most detailed imaging tests for identifying urinary stones because it can show stone size, location, number, density and obstruction. However, the best first test depends on the clinical situation. Ultrasound is often preferred when avoiding radiation is important, including pregnancy and many paediatric cases.
Is CT KUB Necessary For Every Kidney Stone?
No. Not every patient automatically needs CT. The decision depends on symptoms, previous imaging, pregnancy, age, stone history and whether detailed treatment planning is required.
Can Ultrasound Detect Kidney Stones?
Ultrasound can identify many kidney stones and is useful for detecting kidney swelling or hydronephrosis. However, CT can provide more detailed information about stone size, location and density in many situations.
Which Urine Test Is Needed For Kidney Stones?
Urine routine examination and microscopy are commonly used. They can show blood, white blood cells, crystals, urine pH and other findings. A urine culture may also be required when infection is suspected or before a procedure.
Why Is Urine Culture Important Before Kidney Stone Surgery?
A urine culture can detect bacterial infection. Urinary infection combined with stone obstruction can be important clinically, and infection may need treatment before definitive stone surgery depending on the case.
Which Blood Tests Are Done For Kidney Stones?
Commonly considered blood tests include serum creatinine for kidney function and, depending on the situation, CBC, calcium, uric acid and electrolytes. Additional tests are selected according to the patient's medical history and treatment plan.
Do I Need A 24-Hour Urine Test?
Not every first-time stone patient needs a 24-hour urine test. It is more commonly considered in recurrent or high-risk stone formers to evaluate urine volume, calcium, oxalate, citrate, uric acid, sodium and other stone-forming factors.
Should A Passed Kidney Stone Be Tested?
If a stone or stone fragment is available, stone analysis can be useful because knowing the stone composition helps guide more specific prevention advice and metabolic evaluation.
What Does Hydronephrosis Mean In A Kidney Stone Report?
Hydronephrosis means swelling of the kidney's collecting system. A urinary stone can cause this when it obstructs urine flow. The significance depends on the severity of obstruction, symptoms, infection and kidney function.
Can I Send My Kidney Stone Reports Before Visiting?
Yes. If you already have CT KUB, ultrasound, urine, blood or previous treatment reports, you can send them before visiting. If you do not have reports, the required tests can also be advised and arranged after evaluation at the hospital.
When Is A Kidney Stone An Emergency?
Urgent evaluation may be required when stone pain is associated with fever or chills, severe persistent pain, repeated vomiting, difficulty passing urine, significant weakness, a solitary kidney or suspected urinary obstruction with infection.

Have Kidney Stone Reports? Send Them Before Visiting

If you already have CT KUB, ultrasound, urine or blood reports, share them for treatment planning. If you do not have reports yet, the required investigations can also be advised after evaluation at Govinda Healthcare.

Call +91 95929 99184 Send Reports On WhatsApp
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