Kidney stones

Kidney stones

Kidney stones occur when there are high levels of calcium, oxalate, cystine, or uric acid in the urine or when you do not drink enough fluids. Tiny crystals of those substances form and grow in the kidney. Kidney stones are usually asymptomatic and can naturally pass out with urine. If they block the urine flow and cause symptoms, they should be removed. The risk of kidney stones is about 1 in 5 males and 1 in 10 females by age 70.

Risk factors

Diet

• Not drinking enough water
• Frequent eating spinach
• Taking calcium supplements
• Eating a diet low in calcium or phytate (found in rice, rye, wheat, barley, and beans)
• Having a diet high in animal protein, sugars (sucrose, fructose), and sodium

Medical conditions

• Crohn's disease
• Diabetes mellitus
• Gastric or intestinal bypass surgery
• Gout
• Obesity
• Primary hyperparathyroidism

If you have a family history of kidney stones, you have a higher risk of developing the condition. And once you have a kidney stone, the recurrence is high.

Symptoms

You may have had kidney stones for years without any symptoms. The stones may be found accidentally during imaging tests for another medical condition. However, when the stones pass from the kidneys through the urinary tract, they usually cause symptoms as follows:

• Pain often occurs when a stone blocks the urinary tract. The pain can range from mild discomfort to intense pain. However, the pain does not totally disappear without treatment. The renal colic can last for 20-60 minutes. The pain typically starts from the flank or lower abdomen and radiates toward the groin. You may also have pain when urinating.
• Hematuria is when your urine appears pink or reddish. The blood in your urine may be invisible but is detectable in a lab. 
• Gravels are pebble-liked kidney stones in the urine.
• Nausea and vomiting
• Urge to urinate.

Diagnosis

Medical Diagnosis

• Medical history taking and physical examination.
• Non-contrast computed tomography (CT) scan, as a regular X-ray may not detect kidney stones in many instances.
• Ultrasound is usually for people who should avoid radiation exposure, such as children and pregnant women. However, it may not be able to detect small stones or stones in the ureters.

Treatment

Your doctor will determine a suitable treatment approach, depending on the pain level, ability to drink fluids, and size and location of kidney stones. If the pain is tolerable and you can eat and drink, outpatient treatment is possible. If you have severe pain, nausea, or fever, the kidney stones treatment should be in the hospital. Fever may be indicative of an infection. 

Home treatment

• Taking pain relievers such as anti-inflammatory drugs (NSAIDs)
• Take medications to facilitate the passing of kidney stones by relaxing the ureter and allowing kidney stones to pass more quickly. However, you will have to take them for a few weeks until the stone passage.
• Straining your urine to collect the stones may be suggested by your doctor for further analysis. Knowing the type of kidney stones can guide a proper treatment plan to prevent a recurrence. 

Hospital Treatment

Kidney stones larger than 9-10 millimeters rarely pass by themselves and need to be broken down or removed by a urologist.

• Ureteroscopy uses a telescope inserted through the urethra and bladder into the ureter and kidney pelvis to break or remove the stones, particularly if they obstruct the ureter.
• Shock wave lithotripsy (SWL) uses high-energy shock waves to break the stones into smaller pieces and facilitate their passing with the urine. It is suitable for kidney stones 1 cm or smaller in the upper ureter or kidney. This method is ineffective for larger or firm kidney stones. 
• Percutaneous nephrolithotomy (PNL) is a minimally invasive surgical removal of kidney stones with a small telescope. It is effective for removing complex or large kidney stones. 
• If you have asymptomatic stones, consult your doctor for a proper treatment.

Prevention

Recurrences are common once you have a kidney stone. Your doctor may order additional tests to evaluate your health and risk of kidney stones. 

• Urine tests: You will collect all the urine over 24 hours and have it analyzed.
• Passed stone analysis: The stones will be analyzed to check their chemical composition.  
• Blood tests 
• Imaging tests