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Kidney stones (also called renal calculi, nephrolithiasis or urolithiasis) are hard deposits made of minerals and salts that form inside your kidneys.
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.
Read the full article, by Pritish Kumar Halder, in which he discussed Kidney stone- symptoms, diagnosis, causes, and treatments
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A kidney stone usually will not cause symptoms until it moves around within the kidney or passes into one of the ureters. The ureters are the tubes that connect the kidneys and bladder.
If a kidney stone 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 symptoms:
- Severe, sharp pain in the side and back, below the ribs
- Pain that radiates to the lower abdomen and groin
- Pain that comes in waves and fluctuates in intensity
- Pain or burning sensation while urinating
- Other signs and symptoms may include:
- Pink, red or brown urine
- Cloudy or foul-smelling urine
- A persistent need to urinate, urinating more often than usual or urinating in small amounts
- 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.
Kidney stones can be a painful medical issue. The causes of kidney stones vary according to the type of stones.
Not all kidney stones are made up of the same crystals. The different types of kidney stones include:
Calcium stones are the most common Trusted Source. They’re often made of calcium oxalate, though they can consist of calcium phosphate or maleate.
Eating fewer oxalate-rich foods can reduce your risk of developing this type of stone. High-oxalate foods include Trusted Source:
- potato chips
However, even though some kidney stones are made of calcium, getting enough calcium in your diet can prevent stones from forming.
This type of kidney stone is the second most common. They can occur in people with gout, diabetes, obesity, and other types of metabolic syndrome.
This type of stone develops when urine is too acidic. A diet rich in purines can increaseTrusted Source urine’s acidic level. Purine is a colorless substance in animal proteins, such as fish, shellfish, and meats.
This type of stone is found mostly Trusted Source in people with urinary tract infections (UTIs). These stones can be large and cause urinary obstruction.
Struvite stones result from a kidney infection. Treating an underlying infection can prevent the development of struvite stones.
About 1 in 7,000 people worldwide get cystine kidney stones. They occur in both men and women who have the genetic disorder cystinuria.
With this type of stone, cystine — an acid that occurs naturally in the body — leaks from the kidneys into the urine.
Factors that increase your risk of developing kidney stones include:
Family or personal history. If someone in your family has had kidney stones, you’re more likely to develop stones, too. If you’ve already had one or more kidney stones, you’re at increased risk of developing another.
Not drinking enough water each day can increase your risk of kidney stones. People who live in warm, dry climates and those who sweat a lot may be at higher risk than others.
Eating a diet that’s high in protein, sodium (salt) and sugar may increase your risk of some types of kidney stones. This is especially true with a high-sodium diet. Too much salt in your diet increases the amount of calcium your kidneys must filter and significantly increases your risk of kidney stones.
High body mass index (BMI), large waist size and weight gain have been linked to an increased risk of kidney stones.
Digestive diseases and surgery
Gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can cause changes in the digestive process that affect your absorption of calcium and water, increasing the amounts of stone-forming substances in your urine.
Other medical conditions such as renal tubular acidosis, cystinuria, hyperparathyroidism and repeated urinary tract infections also can increase your risk of kidney stones.
Certain supplements and medications, such as vitamin C, dietary supplements, laxatives (when used excessively), calcium-based antacids, and certain medications used to treat migraines or depression, can increase your risk 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.
Types of kidney stones
Knowing the type of kidney stone you have helps determine its cause, and may give clues on how to reduce your risk of getting more kidney stones. If possible, try to save your kidney stone if you pass one so that you can bring it to your doctor for analysis.
Types of kidney stones include:
Most kidney stones are calcium stones, usually in the form of calcium oxalate. Oxalate is a substance made daily by your liver or absorbed from your diet. Certain fruits and vegetables, as well as nuts and chocolate, have high oxalate content.
Dietary factors, high doses of vitamin D, intestinal bypass surgery and several metabolic disorders can increase the concentration of calcium or oxalate in urine.
Calcium stones may also occur in the form of calcium phosphate. This type of stone is more common in metabolic conditions, such as renal tubular acidosis. It may also be associated with certain medications used to treat migraines or seizures, such as topiramate (Topamax, Trokendi XR, Qudexy XR).
Struvite stones form in response to a urinary tract infection. These stones can grow quickly and become quite large, sometimes with few symptoms or little warning.
Uric acid stones
Uric acid stones can form in people who lose too much fluid because of chronic diarrhea or malabsorption, those who eat a high-protein diet, and those with diabetes or metabolic syndrome. Certain genetic factors also may increase your risk of uric acid stones.
These stones form in people with a hereditary disorder called cystinuria that causes the kidneys to excrete too much of a specific amino acid.
How kidney stones are treated
Treatment is tailored according to the type of stone. Urine can be strained and stones collected for evaluation.
Drinking six to eight glasses of water a day increases urine flow. People who are dehydrated or have severe nausea and vomiting may needTrusted Source intravenous fluids.
Other treatment options include:
Pain relief may requireTrusted Source narcotic medications. The presence of infection requires treatment with antibiotics. Other medications include:
- 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) for pain
- acetaminophen (Tylenol) for pain
- naproxen sodium (Aleve) for pain
Extracorporeal shock wave lithotripsy uses sound waves to break up large stones so they can more easily pass down the ureters into your bladder.
This procedure can be uncomfortable and may requireTrusted Source light anesthesia. It can cause bruising on the abdomen and back and bleeding around the kidney and nearby organs.
Tunnel surgery (percutaneous nephrolithotomy)
A surgeon removesTrusted Source the stones through a small incision in your back. A person may need this procedure when:
- the stone causes obstruction and infection or is damaging the kidneys
- the stone has grown too large to pass
- pain can’t be managed
When a stone is stuck in the ureter or bladder, your doctor may use an instrument called a ureteroscope to remove it.
A small wire with a camera attached is inserted into the urethra and passed into the bladder. The doctor then uses a small cage to snag the stone and remove it. The stone is then sent to the laboratory for analysis.
Passing a kidney stone can cause pain and discomfort.
Your doctor may recommend taking an over-the-counter pain reliever, such as acetaminophen or ibuprofen, to help reduce symptoms.
For severe pain, your doctor may also prescribeTrusted Source a narcotic or inject an anti-inflammatory medication, such as ketorolac (Toradol).
Other natural remedies may also provide short-term relief from symptoms, including taking a hot bath or shower or applying a heating pad to the affected area.
Testing for and diagnosing kidney stones
Diagnosis of kidney stones requires a complete health history assessment and a physical exam. Other tests includeTrusted Source:
- 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:
- abdominal X-rays
- intravenous pyelogram (IVP)
- retrograde pyelogram
- ultrasound of the kidney (the preferred test)
- 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’re taking.
Passing a kidney stone
Passing a kidney stone is a process that typically occurs in stages over a period of several weeks.
Here are the stages that occur Trusted Source when passing a kidney stone:
After a kidney stone has formed, you may experience spasms as your kidneys try to push out the stone. This can cause severe pain in your back or side, which may come and go in waves.
During this stage, the stone enters the ureter, which is the tube that connects the kidneys to the bladder. Depending on the size of the stone, this stage can also cause feelings of pain and intense pressure.
Once the stone has reached the bladder, most of the pain will subside. However, you may feel an increased pressure in the bladder and a need to urinate more frequently. In some cases, the stone may temporarily get stuck at the opening of the urethra, which could block the flow of urine.
The final stage occurs once the stone has reached the urethra. During this stage, you need to push hard to pass the kidney stone with the urine through the opening of the urethra.
How long does it take to pass a kidney stone?
The amount of time that it takes to pass a kidney stone can vary depending on the size of the stone. Generally, small stones are able to pass through the urine within 1-2 weeksTrusted Source, often without any treatment.
On the other hand, larger stones may take 2-3 weeks to move through the kidneys and into the bladder.
Stones that don’t pass on their own within 4 weeks typically require medical treatment.
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