kidney stone blood test explained
Informed by recognized medical guidance
Overview
A kidney stone blood test is a lab test that checks your blood for signs of kidney stones. It measures levels of certain substances, like calcium, uric acid, and creatinine, that can help your doctor understand why stones form and how your kidneys are working. This test is often done alongside urine tests and imaging scans to diagnose and manage kidney stones.
Key facts
- Kidney stones are hard deposits made of minerals and salts that form inside your kidneys.
- Blood tests can help find the cause of kidney stones, such as high calcium or uric acid levels.
- The test is simple, quick, and usually done at a clinic or hospital lab.
Yes, kidney stones are common, affecting about 1 in 10 people at some point in their life.
Kidney stones can affect anyone, but they are more common in adults, especially men, and people with certain medical conditions or family history.
Symptoms
- Sudden, severe pain that prevents you from sitting still or finding a comfortable position
- Fever over 101°F (38.3°C) with chills or shaking
- Inability to pass any urine (complete blockage)
- Blood in urine that looks like dark red or has clots
- ⚠Pain that does not improve with over-the-counter pain relievers
- ⚠Nausea or vomiting that prevents you from keeping fluids down
- ⚠Signs of infection, such as fever, chills, or cloudy, foul-smelling urine
Common symptoms
- Severe pain in the back, side, or lower belly that comes and goes
- Pain that spreads to the groin or lower abdomen
- Blood in urine (pink, red, or brown)
- Frequent or painful urination
- Nausea or vomiting
Symptoms in children
- Unexplained crying or irritability in young children
- Frequent urinary tract infections
- Blood in the diaper or toilet
- Pain that makes it hard to sit still
Symptoms in older adults
- Less obvious pain (may be dull ache instead of sharp pain)
- Confusion or fatigue from kidney infection
- Blood in urine or difficulty urinating
- Fever or chills without clear cause
Causes
Main causes
- High levels of calcium, oxalate, or uric acid in the urine
- Not drinking enough fluids, leading to concentrated urine
- Certain medical conditions like gout, hyperparathyroidism, or urinary tract infections
Risk factors
- Family or personal history of kidney stones
- Dehydration or living in a hot, dry climate
- Diet high in salt, sugar, or animal protein
- Obesity or certain digestive diseases (like Crohn’s disease)
- Taking certain medications or supplements (without medical advice)
When to see a doctor
See a doctor urgently if:
- If you have severe pain that does not go away
- If you have fever or signs of infection
- If you cannot pass urine
Book a routine appointment if:
- If you have mild, intermittent pain or blood in urine that is not an emergency
- If you have had a kidney stone before and need follow-up testing
Diagnosis
Doctors diagnose kidney stones using a combination of tests: a blood test, a urine test, and imaging scans like a CT scan or ultrasound. The blood test checks for high levels of stone-forming substances and assesses kidney function.
Tests that may be done
- Blood test: checks calcium, uric acid, creatinine, and other markers
- Urine test: looks for blood, infection, and stone-forming chemicals
- Imaging: CT scan or ultrasound to see the stone's size, location, and any blockage
What to expect at your appointment
The blood test is a simple blood draw from a vein in your arm. You may be asked to fast (not eat or drink for several hours) before the test. Results usually come back within a day or two, and your doctor will explain what they mean.
Treatment
Treatment for kidney stones depends on the size, location, and cause of the stone. Many small stones pass on their own with plenty of water and pain management. Larger stones may need medical help to break them up or remove them.
Self-care at home
- Drink lots of water (at least 2 to 3 liters a day) to help pass the stone
- Take over-the-counter pain relievers as recommended by your doctor
- Apply a heating pad to the painful area for relief
- Strain your urine to catch the stone for analysis
Medical treatments
Doctors may prescribe medications to help relax the ureter and make it easier to pass the stone, or to reduce stone formation. For larger stones, procedures such as shock wave lithotripsy (using sound waves to break the stone) or ureteroscopy (using a thin scope to remove the stone) may be used. Always follow your doctor's advice on treatment options.
When is surgery considered?
Surgery may be needed if the stone is too large to pass, causes severe pain, blocks urine flow, or leads to infection. The most common surgical method is called percutaneous nephrolithotomy, where a small cut in the back is made to remove the stone.
Living with this condition
If you have had kidney stones, it's important to stay well-hydrated and follow your doctor's advice on diet. You may need to drink more water than usual, especially in hot weather or after exercise.
Lifestyle tips
- Drink at least 8 to 10 cups of water daily (more if you sweat a lot)
- Limit foods high in salt, sugar, and animal protein
- Eat fruits and vegetables that are low in oxalate (like bananas, melons, and broccoli)
- Avoid high-dose vitamin C supplements without medical advice
Diet and exercise
A balanced diet with moderate calcium (from foods, not supplements) may help prevent stones. Regular exercise is fine, but drink extra water to replace fluids lost through sweat.
Mental health and emotional wellbeing
Living with kidney stones can be stressful and painful. The recurring pain and worry about future stones may cause anxiety or frustration. Talk to your doctor or a counsellor if you feel overwhelmed.
Prevention
Yes, you can reduce your risk of kidney stones by staying hydrated, eating a healthy diet low in salt and animal protein, and maintaining a healthy weight. If you have a history of stones, your doctor may suggest blood and urine tests to find the cause and tailor prevention.
Vaccines
There are no vaccines for kidney stones.
Screening programmes
There is no routine screening for kidney stones. If you have had stones before, your doctor may recommend periodic check-ups, including blood and urine tests.
Complications
If left untreated
- Blockage of urine flow, causing kidney swelling (hydronephrosis)
- Severe kidney infection (pyelonephritis) that can spread to the blood
- Long-term kidney damage or reduced kidney function
- Recurrence of stones (often within 5 years)
Long-term outlook
With proper treatment and prevention, most people recover fully from kidney stones. Even if you have had them before, making lifestyle changes can greatly lower your risk of getting them again.
Find support
External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.
Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.
Related conditions
Sources and guidance
This article is educational and is prepared with reference to recognized health information and clinical guidance sources where available. Specific source links may vary by topic.
Last updated: July 18, 2026
Educational note: This information is for education only and is not a diagnosis.
Use it to support, not replace, advice from a licensed clinician.
If symptoms are severe, worsening, or urgent, call your local emergency number or seek emergency care.