Kidney Stones

Overview

Kidney stones are one of the most common diseases, with about 12% of the world population affected by it. At least half a million people have to seek medical attention for kidney stone problems. Also known as renal calculi, nephrolithiasis or urolithiasis, kidney stones are the hard deposits of salts and minerals that form inside your kidney.

According to researchers, about one in ten people will get a kidney stone during their life. Talking about the prevalence, the United States witnessed an increase in the disease from 3.8% in the late 1970s to a whopping 8.8% in the late 2000s. Men are more susceptible to kidney stones than women, with 11% of men suffering from kidney stones while 9% of women are affected by it. Talking about the Indian scenario, the National Center for Biotechnology Information estimates that 12% of the population is exposed to kidney stones, with the disease more common in the northern part of the country, at 15%.

Symptoms of Kidney Stones

Kidney stones initially do not cause any kind of symptoms. However, if the stone starts making its way through the kidney or passes through the ureters (tube connecting bladder and kidney), it will start showing symptoms. The following symptoms can be observed:

• Sharp pain in the side and back side, below the ribs
• Pain radiating to the lower abdomen and groin
• Pain coming in waves and fluctuating in intensity
• While urinating, feeling pain or burning sensation
• Change in colour of urine, like pink, red or brown. One can also see blood in the urine.
• Cloudy or foul-smelling urine
• A constant urge to urinate, urinating more often than usual or urinating in small amounts
• Vomiting and feeling nausea
• Fever as well as chills if there is a presence of infection

Causes of Kidney Stones

There is no single known cause of the disorder, however, there are several factors that may increase your risk of getting this disease. If your urine consists of more crystal-forming substances like calcium, oxalate and uric acid—then the fluid in your urine can dilute. Also, there can be a possibility that your urine lacks components that refrain crystals from sticking together. This creates an ideal situation for the formation of kidney stones. Some other causes can include:

• Too much or too little exercise
• Weight loss surgery
• Obesity
• Drinking less water
• Medical conditions like Crohn’s disease and Type II diabetes
• Medications like antibiotics and diuretics
• Family history

Certain types of food can also play a crucial role in the formation of kidney stones. Food that contains high amounts of oxalates should be avoided. Examples include nuts and peanuts, soy products like tofu and soy milk, wheat bran and others. Note that these foods are healthy and one should not cut down these unless the doctor has asked you to do so.

Types
Kidney stones are divided into four categories. Let’s take a look at those types:

• Calcium stones: The majority of kidney stones are calcium stones in the form of calcium oxalate. Oxalate is made by your liver daily and it can be absorbed from food like nuts, chocolate and certain kinds of fruits and vegetables. The amount of oxalate can be increased by high doses of vitamin D, intestinal bypass surgery and several metabolic disorders.

Calcium stones can be further divided into two: Calcium oxalate (61% of all stones in the US) and calcium phosphate (15% of all stones in the US).

• Struvite stones: These stones are composed of magnesium, ammonium, phosphate and calcium carbonate, which is known as struvite and form due to infection with certain kinds of bacteria that produce ammonia. Around 5% to 15% of stones in the US are struvite stones.
• Uric acid stones: They form in people who lose too much fluid because of malabsorption (a condition preventing absorption of nutrients from the small intestine), those consuming high-protein diets, and those with diabetes or metabolic syndrome. 10% to 15% of stones in the US are uric acid stones.
• Cystine stones: Quite rare, they are found in people with an inherited metabolic disorder leading to high levels of the amino acid cystine passing down the urine (cystinuria). Just 1% to 2% of stones in the US are cystine stones.

Tests and Treatments for Kidney Stones

The following methods can be followed for the diagnosis:

• Blood test: Helping in the monitoring of kidneys, the test can reveal if there is too much calcium or uric acid in your blood.
• Urine test: This 24-hour urine collection test can provide information on whether you are excreting too many stone-forming minerals or too few stone-preventing substances.
• Imaging: It can show kidney stones in the urinary tract. High-speed or dual-energy computerised tomography (CT) may reveal even tiny stones. Ultrasound is another option to diagnose kidney stones. Abdominal X-ray can also be performed which can show the location of kidney stones. But keep in mind, not all stones are visible on abdominal X-ray.
• Analysing passed stones: In this, you can be asked to urinate through a strainer so that the stones can be analysed for their composition.

Important things to keep in mind during diagnosis:

• CT scans should be offered to adults
• Ultrasound scans should be offered to pregnant women
• Kids and people under 16 should be offered ultrasounds. If ultrasound does not detect anything, a low-dose, non-contrast CT scan can be considered

There are plenty of treatments depending on the type of stones. A look at them:
For small stones

• Drinking water: Drinking two litres to four litres of water every day will keep your urine dilute and also prevent stones from forming.
• Pain relievers: Stone passing can cause pain and discomfort. To relieve the pain medications like ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) can be taken.
• Medical therapy: To help in the passage of kidney stones, alpha-blockers can help by relaxing the ureter's muscles, with less pain and more quickly. Some common alpha-blockers are tamsulosin (Flomax) and the drug combination dutasteride and tamsulosin (Jalyn).

Some other useful medications are:

• Allopurinol (Zyloprim) for uric acid stones
• Thiazide diuretics to prevent calcium stones from forming
• Sodium bicarbonate or sodium citrate to make the urine less acidic
• Phosphorus solutions to prevent calcium stones from forming
• Ibuprofen (Advil), Acetaminophen (Tylenol) and Naproxen sodium (Aleve) for pain relief

For large stones
Surgery is usually prescribed for large stones. Some of them are:

• Shock wave lithotripsy: The procedure uses sound waves to create strong vibrations that break the kidney stones into smaller pieces. These small stones then pass through the urinary tract. Some side effects include blood in the urine, bruising on the back or abdomen, bleeding around the kidney and other adjacent organs, and discomfort as the fragments pass.
• Ureteroscopy and Cystoscopy: These procedures involve inserting the cystoscope or ureteroscope (long, thin tube) through the urethra to see the urinary tract. Once the stone is found, it can be removed or broken into smaller pieces.
• Surgery: The procedure involves making a small incision and inserting small instruments and telescopes. The stone is either pulled out or broken into smaller pieces using a laser or pneumatic energy. The process is called percutaneous nephrolithotomy.

Mild side effects can include:

• Burning feeling during urinating for a few days after surgery
• Discomfort in the bladder or kidney area when urinating
• Small amounts of blood in the urine
• The need to urinate more frequently
• Temporary pain resulting from surgical tools being inserted into the urinary system
• Stone fragments can cause blocked ureter
• Urinary tract infection (UTI)

Prevention for Kidney Stones

Drinking water and avoiding dehydration are the best prevention methods. Lemonade and orange juice are healthy options. They both contain citrate, which may prevent stones from forming. Other prevention methods you can follow to lead a healthy life are:

• Avoid high-salt diets. Try to avoid processed foods like chips and canned vegetables. High sodium can increase the risk of kidney stones as salts in the urine prevent calcium from being reabsorbed from the urine to the blood, causing high urine calcium.
• Reduce the intake of animal protein like fish, beef and poultry.
• Avoid taking Vitamin C supplements. Studies have found that if high doses of vitamin C are taken regularly, it can double a person’s chances of kidney stones. But no need to worry about natural vitamin C.