Can kidney stones be detected through urine tests

Most patients with kidney stones are male. Genetics, mental stress, bad eating habits and other reasons may lead to kidney stones. Therefore, you should develop good eating habits in normal times, pay attention to rest, and know how to relax yourself properly. In addition to urine tests, you can also undergo B-ultrasound and CT examinations.

Causes

The formation process of kidney stones is that certain factors cause the concentration of crystal substances in the urine to increase or the solubility to decrease, resulting in an oversaturated state. Crystals precipitate and grow and accumulate locally, eventually forming stones. There are many factors that affect the formation of stones. Age, gender, race, genetics, environmental factors, eating habits and occupation are related to the formation of stones. Metabolic abnormalities (such as hyperparathyroidism, hypercortisolism, hyperglycemia), long-term bed rest, nutritional deficiencies (vitamin B6 deficiency, magnesium-deficient diet), urinary tract obstruction, infection, foreign bodies and drug use are common causes of stone formation. It is known that urinary stones have 32 components, the most common of which is calcium oxalate. Other components of stones include magnesium ammonium phosphate, uric acid, calcium phosphate, and cystine (an amino acid). Kidney stones are rarely composed of a single type of crystal. Most are composed of two or more types, with one type being the main component.

Clinical manifestations

The symptoms of kidney stones depend on the size, shape, location, and presence of complications such as infection and obstruction. Most people with kidney stones have no symptoms unless the stone falls from the kidney into the ureter and blocks the flow of urine through the ureter. Common symptoms include lumbar and abdominal cramps, nausea, vomiting, irritability, abdominal distension, hematuria, etc. If combined with urinary tract infection, symptoms such as chills and fever may also occur. Acute renal colic often causes unbearable pain to patients.

1. Asymptomatic

Small stones with smooth surfaces can be excreted in the urine without causing obvious symptoms. Stones that are fixed in the renal pelvis or lower renal calyx and are not infected may also not cause any symptoms. Even large staghorn stones may not cause obvious symptoms for a long time, or may only cause mild discomfort or soreness in the kidney area, if they do not cause obstruction or infection of the renal calyx or renal pelvis.

2. Pain

(1) Distending pain or dull pain is mainly caused by large stones compressing, rubbing or causing water accumulation in the renal pelvis or calyx.

(2) Colic is caused by smaller stones moving in the renal pelvis or ureter, irritating the ureter and causing spasm. The pain often occurs suddenly, starting from the back, waist or ribs, radiating along the ureter to the lower abdomen, inner thighs, and vulva, and may be accompanied by difficulty urinating, nausea and vomiting, profuse sweating, etc.

3. Hematuria

Hematuria is often accompanied by pain. Sometimes the patient has no pain, only hematuria or very little blood that cannot be seen with the naked eye. Physical examinations usually include a urine test, and the sediment after centrifugation of the urine is examined under a microscope. If an excessive number of red blood cells is seen, it means hematuria, which is sometimes an early sign of kidney stones.

4. History of stone removal

When pain and hematuria occur, sand or small stones may be excreted in the urine. When the stone passes through the urethra, there is blockage of urine flow and a stinging sensation in the urethra. After the stone is excreted, the urine flow immediately resumes and the patient feels relaxed and comfortable.

5. Symptoms of infection

When combined with infection, pyuria may occur, and during acute attacks, there may be symptoms of chills, fever, back pain, frequent urination, urgency, and pain when urinating.

6. Renal insufficiency

Obstruction caused by kidney stones on one side may cause hydronephrosis and progressive renal dysfunction on that side; obstruction caused by bilateral kidney stones or solitary kidney stones may develop into renal insufficiency.

7. Urinary retention

Bilateral renal stones causing urinary tract obstruction on both sides, solitary kidney or only functional kidney stone obstruction may cause urinary retention, and reflex urinary retention may occur on the other side if one side is obstructed by a renal stone.

8. Lumbar mass

When severe hydronephrosis is caused by stone obstruction, a mass may be felt in the waist or upper abdomen.

examine

1. Urine test

It can detect the presence of urine sugar, urine protein, red blood cells, white blood cells, crystals, bacteria, etc.

2. Blood test

If a routine blood test finds that the white blood cell count is too high, it may indicate an infection. Blood can also be drawn to check kidney function and blood calcium concentration.

3. X-ray examination

X-ray examination is the most important method for diagnosing urinary stones. Including urinary tract plain film, excretory urography, retrograde pyelography, percutaneous renal puncture angiography, etc.

4.B-ultrasound examination

It can diagnose the presence of kidney stones and other associated lesions, and determine whether there is water accumulation in the kidneys. It can especially detect X-ray translucent stones, and can also provide certain evidence for the kidney damage caused by stones and the causes of certain stones. However, B-ultrasound also has certain limitations. It cannot distinguish between renal calcification and stones, cannot intuitively understand the relationship between stones and kidneys, and cannot see the specific impact of stones on the kidneys. More importantly, B-ultrasound cannot provide sufficient evidence on how to treat stones.

5. CT examination

CT examination is currently the first choice for diagnosing stones. CT examination can show the kidney size, contour, kidney stones, hydronephrosis, renal parenchymal lesions and the remaining renal parenchyma, and can also distinguish renal cysts or hydronephrosis; it can identify the causes of urinary tract obstruction caused by other factors outside the urinary tract, such as retroperitoneal tumors, pelvic tumors, etc.; enhanced angiography can understand the function of the kidneys; for acute renal failure caused by stones, CT helps to establish the diagnosis.

6. Magnetic resonance

The combination of MRI water imaging and MRI original images is more accurate and comprehensive, and is very effective in diagnosing urinary tract dilatation, especially for those with renal damage, contrast agent allergy, and contraindications to X-ray examination. It is also suitable for pregnant women and children.

7. Physical examination

When renal colic occurs, there is percussion pain and tenderness in the affected kidney area. In cases without obstruction, physical examination may show no positive signs or only mild percussion pain in the affected area.