Blood Test for Kidney Stones - What to Expect, Report Value

Kidney stones are one of the most painful and common urological conditions. This condition is caused by the accumulation of salt and mineral deposits in the kidneys, which can then travel down the urinary tract, causing blockages. In India, around 12% of the population is suffering from kidney stone disease (KSD).

Kidney stones can occur by a variety of factors, including diet, genetics, insufficient water intake, and certain medical conditions (gout, high blood pressure, diabetes, etc.). Irrespective of the cause, their symptoms can range from mild discomfort to excruciating pain.

These irregular-shaped solid crystals can range in size from a grain of sand to a golf ball. You may not even realise that you have kidney stones if their size is too small. However, even small stones can cause extreme pain if they get stuck in the urinary tract.

If a large kidney stone gets trapped in your urinary tract, it can cause bleeding and make it difficult for you to pass urine. In this case, you need surgery to remove the stones.

Diagnosing kidney stones usually involves a detailed medical history taking, followed by a physical examination, laboratory tests, and imaging tests. These tests are as follows.

1. Medical history: The doctor first records a complete medical history. They will gather information about current symptoms, medical conditions, previous kidney stone events, dietary history, medications, and family history.
2. Physical examination: The doctor will perform a physical examination to evaluate the signs of kidney stones, including pain in the lower back, flank (sides), or groin.
3. Blood tests for kidney stones: Blood tests are one of the key diagnostic tools used by doctors to diagnose kidney stones. They help to determine high levels of a particular mineral in the blood that is causing kidney stones.
   The doctor will test your blood for calcium, uric acid, and phosphorus. Several different blood tests for kidney stones are: 
   1. Basic metabolic panel (BMP): A BMP measures the levels of several different substances in the blood, including electrolytes (sodium, potassium, chloride, bicarbonate), glucose, calcium, blood urea nitrogen (BUN), and creatinine.
      Abnormal levels of these substances can indicate an underlying medical condition that may be contributing to the formation of kidney stones.
   2. C-reactive protein (CRP): CRP is a protein that is produced in response to inflammation in the body. Elevated levels of CRP can indicate the presence of an infection, which may be present in kidney stones.
4. Urine tests: Urine tests can help doctors identify any underlying medical conditions that may be contributing to the formation of kidney stones.
   For example, a urinalysis can help doctors identify the presence of blood in the urine (a sign of a kidney stone) and minerals that are causing kidney stones (excess calcium).
   The presence of bacteria and white blood cells in the urine may indicate a urinary tract infection.
5. Imaging tests: Even though all the above-mentioned tests are essential, a kidney stone can only be confirmed by radiological testing. In most cases, a simple Kidney-ureter-bladder (KUB) x-ray will be suitable to detect a kidney stone.
   However, if your doctor needs more details, they may suggest a computed tomography (CT) scan or intravenous pyelogram (IVP).
   1. KUB test for kidney stones: This helps to determine the location and the size of the stone. Often, a KUB x-ray is obtained by the doctors to determine if the kidney stone is suitable for shock wave treatment.
   2. Intravenous pyelogram (IVP): IVP is a special type of X-ray in which a dye is injected to obtain an X-ray of the urinary system.
   3. CT scan: CT scans use a combination of computer technology and X-ray to create images of the urinary tract.
      It helps to determine the location and size of the kidney stone, conditions that may have caused the kidney stone formation, and if the stone is blocking the urinary tract.

Blood tests are an essential tool for diagnosing and monitoring kidney stones, as well as assessing overall kidney function. According to the American Kidney Fund, blood tests help

1. Identify underlying causes of kidney stones, such as high levels of calcium, uric acid, or other substances in the blood.
2. Assess kidney function. Creatinine is a waste product produced by the muscles and excreted by the kidneys.
   Elevated levels of creatinine in the blood can be a sign of kidney damage or dysfunction, which can occur as a result of kidney stones.
3. Monitor the effectiveness of treatment for kidney stones.
4. Detect signs of infection. e.g, elevated white blood cells.

Overall, blood tests are just one tool that doctors use for diagnosing kidney stones. Other tests like urinalysis, imaging tests, etc., are often used in conjunction with blood tests to provide comprehensive information and accurate diagnosis.

There are several types of blood tests that can be used to diagnose and monitor kidney stones. These tests measure levels of different substances in the blood that can help identify the underlying causes of kidney stones and assess kidney function.

Here are some of the most common blood tests used for kidney stones:

1. Complete Blood Count (CBC): This test measures levels of red blood cells, white blood cells, and platelets in the blood. While a CBC is not specific to kidney stones, it can help identify infections or inflammation that may be contributing to the condition.
2. Electrolyte Panel: This test measures levels of sodium, potassium, calcium, and other electrolytes in the blood. High levels of calcium or uric acid can contribute to the formation of kidney stones, so this test can help identify these underlying causes.
3. Creatinine and Blood Urea Nitrogen (BUN): These tests measure levels of waste products in the blood that are normally excreted by the kidneys.
   High levels of creatinine or BUN can be a sign of kidney damage or dysfunction, which can occur as a result of kidney stones.
4. Parathyroid Hormone (PTH) Test: This test measures levels of PTH in the blood, which can help identify hyperparathyroidism, a condition in which the parathyroid glands produce too much PTH.
   This can lead to high levels of calcium in the blood, which can contribute to the formation of kidney stones.

A blood test for kidney stone is a simple and routine procedure that involves the following steps:

1. You will be told to sit on the chair and the healthcare provider (phlebotomist) will check your arms for an easily accessible vein in your elbow.
2. They will clean and disinfect the area after locating the vein.
3. A small needle will be inserted into the vein to withdraw blood.
4. The blood is collected in a test tube and the provider will remove the needle as they have sufficient blood to test.
5. They will place a gauze or a cotton ball on the site to stop the bleeding.
6. The provider will then send the blood sample to a laboratory for testing.

Depending on the specific tests that your doctor has ordered, the results may be available within a few hours or several days. The entire procedure for the blood test usually takes less than 5 minutes.

Interpreting the results of a blood test for kidney stones requires the expertise of a healthcare professional, as the results can vary depending on the specific tests that were performed and the individual patient's medical history.

Here are some general guidelines for interpreting the most common blood tests used for kidney stones:

1. Complete Blood Count (CBC): A CBC measures levels of red blood cells, white blood cells, and platelets in the blood. 
   1. The normal ranges of the contents of CBC are as follows:
      1. RBC count: Female: 4.2 to 5.4 million cells/mcL; Male: 4.7 to 6.1 million cells/mcL
      2. WBC count: 4,500 to 10,000 cells/mcL
      3. Haemoglobin: Female: 12.1 to 15.1 gm/dL; Male: 13.8 to 17.2 gm/dL
      4. Haematocrit: Female: 36.1 to 44.3%; Male: 40.7 to 50.3%
      5. Red blood cell indices: 
         1. Mean corpuscular volume (MCV): 80 to 95 femtoliter
         2. Mean corpuscular haemoglobin (MCH): 27 to 31 pg/cell
         3. Mean corpuscular haemoglobin concentration (MCHC): 32 to 36 gm/dL
      6. Platelet count: 150,000 to 4,50,000/dL
      7. CRP level: Less than 0.9 mg/dL
      8. Glucose level: Fasting blood glucose level: 70-99 mg/dL
   2. Abnormal results may indicate an infection or inflammation, which can contribute to the formation of kidney stones.
2. Electrolyte Panel: An electrolyte panel measures levels of sodium, potassium, calcium, and other electrolytes in the blood. 
   1. The normal ranges of the electrolyte panel are as follows:
      1. Potassium: 3.5 to 5 mmol/L
      2. Sodium: 136 to 145 mmol/L
      3. Chloride: 96 to 106 mmol/L
      4. Bicarbonate level: 22 to 32 mmol/L
   2. High levels of calcium or uric acid may indicate an underlying cause of kidney stones, such as hyperparathyroidism or gout.
3. Creatinine and Blood Urea Nitrogen (BUN): Creatinine and BUN tests measure levels of waste products in the blood that are normally excreted by the kidneys. 
   1. The normal ranges:
      1. Creatinine level: Females: 0.5 to 1.1 mg/dL; Males: 0.7 to 1.3 mg/dL.
      2. BUN level: Female: 6 to 21 mg/dL; Male: 8 to 24 mg/dL; Children (1-17 years): 7 to 20 mg/dL
   2. High levels may indicate kidney damage or dysfunction, which can occur as a result of kidney stones.
4. Parathyroid Hormone (PTH) Test: A PTH test measures levels of PTH in the blood. 
   1. The normal range of this test is 10 to 55 picograms per millilitre (pg/mL).
   2. High levels may indicate hyperparathyroidism, which can contribute to the formation of kidney stones.

Several factors can affect the results of blood tests used to diagnose kidney stones. These include:

1. Medications: Certain medications can affect the levels of substances in the blood that are measured in kidney stone blood tests.
   For example, diuretics can increase urine output and decrease blood volume, which can affect electrolyte levels.
   It is important to inform your healthcare provider of any medications you are taking before undergoing blood tests for kidney stones.
2. Dehydration: Dehydration can affect the concentration of substances in the blood and urine, which can affect the results of kidney stone blood tests. It is important to stay well-hydrated before undergoing blood tests for kidney stones.
3. Time of day: Some substances, such as calcium and PTH, may have higher levels in the blood in the morning compared to later in the day. It is important to follow your healthcare provider's instructions regarding when to undergo blood tests for kidney stones.
4. Medical conditions: Certain medical conditions, such as hyperparathyroidism or chronic kidney disease, can affect the levels of substances in the blood that are measured in kidney stone blood tests.
5. Dietary factors: Certain foods, such as those high in calcium or oxalate, can affect the levels of these substances in the blood and urine. It is important to follow any dietary instructions provided by your healthcare provider before undergoing blood tests for kidney stones.

The next steps after a blood test for kidney stones depend on the results and the individual patient's medical history. Here are some general guidelines:

1. Normal Results: If the results of the blood test are normal, further testing may not be necessary. Your healthcare provider may recommend lifestyle changes, such as drinking more water and avoiding certain foods that can contribute to kidney stone formation.
2. Abnormal Results: If the results of the blood test are abnormal, your healthcare provider may recommend further testing to determine the cause of the abnormalities.
   This may include imaging tests, such as an ultrasound or CT scan, or additional blood and urine tests.
3. Referral to a Specialist: If the abnormalities are severe or the cause is unclear, your healthcare provider may refer you to a specialist, such as a nephrologist or a urologist, for further evaluation and treatment.
4. Treatment: Treatment for kidney stones depends on the size and location of the stones, as well as the individual patient's medical history. Treatment options may include medications to help pass the stones, procedures to break up or remove the stones, or surgery in rare cases.

Kidney stones are a painful and common urological condition. Blood tests for kidney stones include blood and urine tests as well as imaging tests. By working with your doctor and undergoing the necessary tests, you can help diagnose kidney stones and develop an effective treatment plan.

If you still have any questions related to blood tests for kidney stones, feel free to contact our personal care team at HexaHealth. We are always happy to help! Our team will guide you thoroughly and solve all your queries. You can also visit our website HexaHealth if you want to learn more about blood tests for kidney stones or other related information.

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