Kidney Stones

<h2 >Causes</h2>

Dietary factors that increase the risk of stone formation include <a href="http://en.wikipedia.org/wiki/Dehydration" title="Dehydration" >low fluid intake</a> and high dietary intake of animal <a href="http://en.wikipedia.org/wiki/Protein" title="Protein" >protein</a>, <a href="http://en.wikipedia.org/wiki/Sodium" title="Sodium" >sodium</a>, refined <a href="http://en.wikipedia.org/wiki/Sugar" title="Sugar" >sugars</a>, <a href="http://en.wikipedia.org/wiki/Fructose" title="Fructose" >fructose</a> and <a href="http://en.wikipedia.org/wiki/High_fructose_corn_syrup" title="High fructose corn syrup" class="mw-redirect" >high fructose corn syrup</a>,<a href="http://en.wikipedia.org/wiki/Kidney_stones#cite_note-HFCS-4" >[5]</a><a href="http://en.wikipedia.org/wiki/Oxalate" title="Oxalate" >oxalate</a>, <a href="http://en.wikipedia.org/wiki/Grapefruit_juice" title="Grapefruit juice" >grapefruit juice</a>, <a href="http://en.wikipedia.org/wiki/Apple_juice" title="Apple juice" >apple juice</a>, and <a href="http://en.wikipedia.org/wiki/Cola" title="Cola" >cola</a> drinks.<a href="http://en.wikipedia.org/wiki/Kidney_stones#cite_note-Johri2010-5" >[6]</a>

A kidney stone, also known as a renal calculus (from the <a href="http://en.wikipedia.org/wiki/Latin" title="Latin" >Latin</a> ren, "kidney" and<a href="http://en.wikipedia.org/wiki/Calculus_(medicine)" title="Calculus (medicine)" >calculus</a>, "pebble") is a solid <a href="http://en.wikipedia.org/wiki/Enterolith" title="Enterolith" >concretion</a> or <a href="http://en.wikipedia.org/wiki/Crystal" title="Crystal" >crystal</a> aggregation formed in the kidneys from<a href="http://en.wikipedia.org/wiki/Dietary_mineral" title="Dietary mineral" >dietary minerals</a> in the <a href="http://en.wikipedia.org/wiki/Urine" title="Urine" >urine</a>. <a href="http://en.wikipedia.org/wiki/Urolithiasis" title="Urolithiasis" >Urinary stones</a> are typically classified by their location in the<a href="http://en.wikipedia.org/wiki/Kidney" title="Kidney" >kidney</a> (nephrolithiasis), <a href="http://en.wikipedia.org/wiki/Ureter" title="Ureter" >ureter</a> (ureterolithiasis), or <a href="http://en.wikipedia.org/wiki/Urinary_bladder" title="Urinary bladder" >bladder</a> (<a href="http://en.wikipedia.org/wiki/Bladder_stone" title="Bladder stone" >cystolithiasis</a>), or by their chemical composition (<a href="http://en.wikipedia.org/wiki/Calcium" title="Calcium" >calcium</a>-containing, <a href="http://en.wikipedia.org/wiki/Struvite" title="Struvite" >struvite</a>, <a href="http://en.wikipedia.org/wiki/Uric_acid" title="Uric acid" >uric acid</a>, or other compounds). About 80% of those with kidney stones are men. Men most commonly experience their first episode between 30 and 40 years of age, while for women the age at first presentation is somewhat later.

Kidney stones typically leave the body by passage in the urine stream, and many stones are formed and passed without causing symptoms. If stones grow to sufficient size (usually at least 3 millimeters (0.12 in)) they can cause obstruction of the ureter. Ureteral obstruction causes <a href="http://en.wikipedia.org/wiki/Postrenal_azotemia" title="Postrenal azotemia" class="mw-redirect" >postrenal azotemia</a> and <a href="http://en.wikipedia.org/wiki/Hydronephrosis" title="Hydronephrosis" >hydronephrosis</a> (distension and dilation of the<a href="http://en.wikipedia.org/wiki/Renal_pelvis" title="Renal pelvis" >renal pelvis</a> and <a href="http://en.wikipedia.org/wiki/Major_calyx" title="Major calyx" >calyces</a>), as well as <a href="http://en.wikipedia.org/wiki/Spasm" title="Spasm" >spasm</a> of the ureter. This leads to <a href="http://en.wikipedia.org/wiki/Pain" title="Pain" >pain</a>, most commonly felt in the <a href="http://en.wikipedia.org/wiki/Torso" title="Torso" class="mw-redirect" >flank</a> (the area between the ribs and hip), lower abdomen, and <a href="http://en.wikipedia.org/wiki/Groin" title="Groin" >groin</a>(a condition called <a href="http://en.wikipedia.org/wiki/Renal_colic" title="Renal colic" >renal colic</a>). Renal colic can be associated with <a href="http://en.wikipedia.org/wiki/Nausea" title="Nausea" >nausea</a>, <a href="http://en.wikipedia.org/wiki/Vomiting" title="Vomiting" >vomiting</a>, <a href="http://en.wikipedia.org/wiki/Fever" title="Fever" >fever</a>,<a href="http://en.wikipedia.org/wiki/Hematuria" title="Hematuria" >blood in the urine</a>, <a href="http://en.wikipedia.org/wiki/Pyuria" title="Pyuria" >pus</a> in the urine, and <a href="http://en.wikipedia.org/wiki/Dysuria" title="Dysuria" >painful urination</a>. Renal colic typically comes in waves lasting 20 to 60 minutes, beginning in the flank or lower back and often radiating to the groin or genitals. The <a href="http://en.wikipedia.org/wiki/Medical_diagnosis" title="Medical diagnosis" >diagnosis</a> of kidney stones is made on the basis of information obtained from the <a href="http://en.wikipedia.org/wiki/Medical_history" title="Medical history" >history</a>, <a href="http://en.wikipedia.org/wiki/Physical_examination" title="Physical examination" >physical examination</a>, <a href="http://en.wikipedia.org/wiki/Urinalysis" title="Urinalysis" >urinalysis</a>, and <a href="http://en.wikipedia.org/wiki/Projectional_radiography" title="Projectional radiography" >radiographic</a> studies.

<a href="http://en.wikipedia.org/wiki/Medical_ultrasonography" title="Medical ultrasonography" >Ultrasound examination</a> and <a href="http://en.wikipedia.org/wiki/Blood_test" title="Blood test" >blood tests</a> may also aid in the diagnosis.

When a stone causes no symptoms, <a href="http://en.wikipedia.org/wiki/Watchful_waiting" title="Watchful waiting" >watchful waiting</a> is a valid option. For symptomatic stones, <a href="http://en.wikipedia.org/wiki/Analgesic" title="Analgesic" >pain control</a> is usually the first measure, using medications such as <a href="http://en.wikipedia.org/wiki/Nonsteroidal_anti-inflammatory_drug" title="Nonsteroidal anti-inflammatory drug" class="mw-redirect" >nonsteroidal anti-inflammatory drugs</a> or <a href="http://en.wikipedia.org/wiki/Opioid" title="Opioid" >opioids</a>. More severe cases may require surgical intervention. For example, some stones can be shattered into smaller fragments using <a href="http://en.wikipedia.org/wiki/Extracorporeal_shock_wave_lithotripsy" title="Extracorporeal shock wave lithotripsy" >extracorporeal shock wave lithotripsy</a>. Some cases require more <a href="http://en.wikipedia.org/wiki/Invasiveness_of_surgical_procedures" title="Invasiveness of surgical procedures" >invasive</a> forms of surgery. Examples of these are <a href="http://en.wikipedia.org/wiki/Cystoscopy" title="Cystoscopy" >cystoscopic</a> procedures such as <a href="http://en.wikipedia.org/wiki/Laser_lithotripsy" title="Laser lithotripsy" >laser lithotripsy</a> or <a href="http://en.wikipedia.org/wiki/Percutaneous" title="Percutaneous" >percutaneous</a> techniques such as <a href="http://en.wikipedia.org/wiki/Percutaneous_nephrolithotomy" title="Percutaneous nephrolithotomy" >percutaneous nephrolithotomy</a>. Sometimes, a tube (<a href="http://en.wikipedia.org/wiki/Ureteric_stent" title="Ureteric stent" >ureteral stent</a>) may be placed in the ureter to bypass the obstruction and alleviate the symptoms, as well as to prevent ureteral stricture after ureteroscopic stone removal.