Kidney Stones: Things To Know About It Including Preventive Measures.

Kidney Stones: Things To Know About It Including Preventive Measures.

What are kidney stones?

Kidney stones (also called renal calculi, nephrolithiasis or urolithiasis) are hard deposits made of minerals and salts that form inside your kidneys.

Urine contains many dissolved minerals and salts. When your urine has high levels of these minerals and salts, you can form stones. Kidney stones can start small but can grow larger in size, even filling the inner hollow structures of the kidney. Some stones stay in the kidney, and do not cause any problems. Sometimes, the kidney stone can travel down the ureter, the tube between the kidney and the bladder. If the stone reaches the bladder, it can be passed out of the body in urine. If the stone becomes lodged in the ureter, it blocks the urine flow from that kidney and causes pain.

  The Kidneys and Urinary System

The kidneys are fist-size organs that handle the body's fluid and chemical levels. Most people have two kidneys, one on each side of the spine behind the liver, stomach, pancreas and intestines. Healthy kidneys clean waste from the blood and remove it in the urine. They control the levels of sodium, potassium and calcium in the blood.

The kidneys, ureters and bladder are part of your urinary tract. The urinary tract makes, transports, and stores urine in the body. The kidneys make urine from water and your body's waste. The urine then travels down the ureters into the bladder, where it is stored. Urine leaves your body through the urethra.

Kidney stones form in the kidney. Some stones move from the kidney into the ureter. The ureters are tubes leading from the kidneys to the bladder. If a stone leaves the kidney and gets stuck in the ureter, it is called a ureteral stone.

Diet, excess body weight, some medical conditions, and certain supplements and medications are among the many causes of kidney stones. Kidney stones can affect any part of your urinary tract  from your kidneys to your bladder. Often, stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together.

Passing kidney stones can be quite painful, but the stones usually cause no permanent damage if they're recognized in a timely fashion. Depending on your situation, you may need nothing more than to take pain medication and drink lots of water to pass a kidney stone. In other instances for example, if stones become lodged in the urinary tract, are associated with a urinary infection or cause complications — surgery may be needed.

Your doctor may recommend preventive treatment to reduce your risk of recurrent kidney stones if you're at increased risk of developing them again.

 Types of kidney stones

1. Calcium stones are the most common type of kidney stones. They are usually made of calcium and oxalate (a natural chemical found in most foods), but are sometimes made of calcium and phosphate.

2. Uric acid stones form when your urine is often too acidic. Uric acid can form stones by itself or with calcium.

3. Struvite stones can happen when you have certain types of urinary tract infections in which bacteria make ammonia that builds up in your urine. Struvite stones are made of magnesium, ammonium and phosphate.

4. Cystine stones are made of a chemical that your body makes naturally, called cystine. Cystine stones are very rare, and happen in people who have a genetic disorder that causes cystine to leak from the kidneys into the urine.

Kidney stones can be as small as a grain of sand or as large sometimes larger than a pearl. They can stay in your kidneys or travel through your ureters (the tubes that go from your kidneys to your bladder), and out of your body with your urine. When a kidney stone moves through your ureters and out your urethra with your urine, it is called passing a kidney stone. A kidney stone can also get stuck in your urinary tract and block urine from getting through. When you pass a kidney stone or a large kidney stone blocks the flow of your urine, it can be very painful.

 Causes of kidney stones

Kidney stones often have no definite, single cause, although several factors may increase your risk.

Kidney stones form when your urine contains more crystal-forming substances such as calcium, oxalate and uric acid, than the fluid in your urine can dilute. At the same time, your urine may lack substances that prevent crystals from sticking together, creating an ideal environment for kidney stones to form.

 Risk factors for kidney stones

The greatest risk factor for kidney stones is making less than 1 liter of urine per day. This is why kidney stones are common in premature infants who have kidney problems. However, kidney stones are most likely to occur in people between the ages of 20 and 50.

Different factors can increase your risk of developing a stone. In the United States, white people are more likely to have kidney stones than black people.

Sex also plays a role. More men than women develop kidney stones, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

A history of kidney stones can increase your risk. So does a family history of kidney stones.

Other risk factors include:

Increase calcium absorption

Dehydration

Obesity

A diet with high levels of protein, salt, or glucose

Hyperparathyroid condition

Gastric bypass surgery

Inflammatory bowel diseases that increase calcium absorption

Taking medications such as triamterene diuretics, antiseizure drugs, and calcium-based antacids.

What are symptoms of kidney stones?

A kidney stone usually will not cause symptoms until it moves around within your kidney or passes into your ureters, the tubes connecting the kidneys and the bladder. If it becomes lodged in the ureters, it may block the flow of urine and cause the kidney to swell and the ureter to spasm, which can be very painful. At that point, you may experience these signs and symptoms:

Pain that radiates to the lower abdomen and groin

Severe, sharp pain in the side, back and below the ribs

Pain that comes in waves and fluctuates in intensity

Pain or burning sensation while urinating.

Other signs and symptoms may include:

A persistent need to urinate, urinating more often than usual or urinating in small amounts

Pink, red or brown urine

Cloudy or foul-smelling urine

Nausea and vomiting

Fever and chills if an infection is present

Pain caused by a kidney stone may change for instance, shifting to a different location or increasing in intensity  as the stone moves through your urinary tract.

When to see a doctor

Make an appointment with your doctor if you have any signs and symptoms that worry you.

Seek immediate medical attention if you experience:

Pain so severe that you can't sit still or find a comfortable position

Pain accompanied by nausea and vomiting

Pain accompanied by fever and chills

Blood in your urine

Difficulty passing urine.

How to diagnose kidney stones?

Diagnosis of kidney stones requires a complete health history assessment and a physical exam.

Other tests include:

Blood tests for calcium, phosphorus, uric acid, and electrolytes.

Blood urea nitrogen (BUN) and creatinine to assess kidney functioning.

Urinalysis to check for crystals, bacteria, blood, and white cells.

Examination of passed stones to determine their type.

The following tests can rule out obstruction:

ultrasound of the kidney (the preferred test)

abdominal X-rays

intravenous pyelogram (IVP)

retrograde pyelogram

MRI scan of the abdomen and kidneys

abdominal CT scan.

The contrast dye used in the CT scan and the IVP can affect kidney function. However, in people with normal kidney function, this isn’t a concern.

There are some medications that can increase the potential for kidney damage in conjunction with the dye. Make sure your radiologist knows about any medications you are taking.

Why kidney stones can be a problem?

Stones don’t always stay in the kidney. Sometimes they pass from the kidney into the ureters. Ureters are small and delicate, and the stones may be too large to pass smoothly down the ureter to the bladder.

Passage of stones down the ureter can cause spasms and irritation of the ureters. This causes blood to appear in the urine.

Sometimes stones block the flow of urine. This is called a urinary obstruction. Urinary obstructions can lead to kidney infection and kidney damage.

What are the treatments for kidney stones?

The treatment for a kidney stone depends on the size of the stone, what it is made of, whether it is causing pain and whether it is blocking your urinary tract. To answer these questions and to figure out the right treatment for you, your doctor might ask you to have a urine test, blood test, x-ray and/or CT scan. A CT scan sometimes uses contrast dye. If you have ever had a problem with contrast dye, be sure to tell your doctor about it before you have your CT scan.

If your test results show that your kidney stone is small, your doctor may tell you to take pain medicine and drink plenty of fluids to help push the stone through your urinary tract. If your kidney stone is large, or if it is blocking your urinary tract, additional treatment may be necessary.

One treatment option is shock wave lithotripsy. This treatment uses shock waves to break up the kidney stones into small pieces. After the treatment, the small pieces of the kidney stone will pass through your urinary tract and out of your body with your urine. This treatment usually takes 45 minutes to one hour and may be done under general anesthesia, which means you will be asleep and unable to feel pain.

Another treatment option is ureteroscopy. This treatment is also done under general anesthesia. The doctor uses a long tool shaped like a tube to find and remove the stone or to find and break the stone into small pieces. If the stone is small, the doctor may be able to remove it. If it is large, it may need to be broken into pieces. In this case, a laser will be used to break the stone into pieces that are small enough to pass through your urinary tract.

In rare cases, a surgery called percutaneous nephrolithotomy is needed to remove a kidney stone. During the surgery, a tube will be inserted directly into your kidney to remove the stone. You will need to be in the hospital for two to three days to have and recover from this treatment.

Can children get kidney stones?

Kidney stones are found in children as young as 5 years. In fact, this problem is so common in children that some hospitals conduct 'stone' clinics for pediatric patients. The increase in the United States has been attributed to several factors, mostly related to food choices. The two most important reasons are not drinking enough fluids and eating foods that are high in salt. Kids should eat less salty potato chips and French fries. There are other salty foods: sandwich meats, canned soups, packaged meals, and even some sports drinks. Sodas and other sweetened beverages can also increase the risk of stones if they contain high fructose corn syrup.

How to prevent kidney stones?

Prevention of kidney stones may include a combination of lifestyle changes and medications.

Lifestyle changes

You may reduce your risk of kidney stones if you:

I. Drink water throughout the day

For people with a history of kidney stones, doctors usually recommend drinking enough fluids to pass about 2.1 quarts (2 liters) of urine a day. Your doctor may ask that you measure your urine output to make sure that you're drinking enough water.

If you live in a hot, dry climate or you exercise frequently, you may need to drink even more water to produce enough urine. If your urine is light and clear, you're likely drinking enough water.

II. Eat fewer oxalate-rich foods. If you tend to form calcium oxalate stones, your doctor may recommend restricting foods rich in oxalates. These include rhubarb, beets, okra, spinach, Swiss chard, sweet potatoes, nuts, tea, chocolate, black pepper and soya products.

III. Choose a diet low in salt and animal protein. Reduce the amount of salt you eat and choose nonanimal protein sources, such as legumes. Consider using a salt substitute, such as Mrs. Dash.

IV. Continue eating calcium-rich foods, but use caution with calcium supplements. Calcium in food doesn't have an effect on your risk of kidney stones. Continue eating calcium-rich foods unless your doctor advises otherwise.

Ask your doctor before taking calcium supplements, as these have been linked to increased risk of kidney stones. You may reduce the risk by taking supplements with meals. Diets low in calcium can increase kidney stone formation in some people.

Ask your doctor for a referral to a dietitian who can help you develop an eating plan that reduces your risk of kidney stones.

Medications for kidney stones

Medications can control the amount of minerals and salts in the urine and may be helpful in people who form certain kinds of stones. The type of medication your doctor prescribes will depend on the kind of kidney stones you have. 

Here are some examples:

Calcium stones

To help prevent calcium stones from forming, your doctor may prescribe a thiazide diuretic or a phosphate-containing preparation.

Uric acid stones 

Your doctor may prescribe allopurinol (Zyloprim, Aloprim) to reduce uric acid levels in your blood and urine and a medicine to keep your urine alkaline. In some cases, allopurinol and an alkalizing agent may dissolve the uric acid stones.

Struvite stones

To prevent struvite stones, your doctor may recommend strategies to keep your urine free of bacteria that cause infection, including drinking fluids to maintain good urine flow and frequent voiding. In rare cases long-term use of antibiotics in small or intermittent doses may help achieve this goal. For instance, your doctor may recommend an antibiotic before and for a while after surgery to treat your kidney stones.

Cystine stones

Along with suggesting a diet lower in salt and protein, your doctor may recommend that you drink more fluids so that you produce a lot more urine,. If that alone doesn't help, your doctor may also prescribe a medication that increases the solubility of cystine in your urine.

Sources:

www.kidneyfund.com

www.kidney.org

+3 other sources