The biggest kidney stone on record weighed more than a kilogram and was 17 centimeters in diameter.
记载在册最大的肾结石重量超过了一公斤，而直径高达17厘米。
The patient didn't actually swallow a stone the size of a coconut.
这位病人并不是吞下了一块椰子大小的石头。
Kidney stones form inside the body, but unfortunately, they're extremely painful to get out.
肾结石是在人体内部形成的，然而糟心的是，要把它们取出来非常痛苦。
A kidney stone is a hard mass of crystals that can form in the kidneys, ureters, bladder, or urethra.
肾结石是一块坚硬的结晶，在肾脏、尿管、膀胱或者尿道中形成。
Urine contains compounds that consist of calcium, sodium, potassium, oxalate, uric acid, and phosphate.
尿液中的一些物质含有钙、钠、钾、草酸盐、尿酸、还有磷。
If the levels of these particles get too high,
如果这些微粒的含量过高，
or if urine becomes too acidic or basic, the particles can clump together and crystallize.
或者尿液变得过酸或过碱，这些微粒就很容易聚集在一起，然后结晶。
Unless the problem is addressed,
如果不及时扼制，
the crystals will gradually grow over a few weeks months, or even years, forming a detectable stone.
随着时间流逝，结晶将会一周周、一月月、甚至一年年继续变大，直到慢慢形成了可检测到的石头。
Calcium oxalate is the most common type of crystal to form this way, and accounts for about 80% of kidney stones.
草酸钙是这个过程中最常见的结晶，大约80%的肾结石的成分是草酸钙。
Less common kidney stones are made of calcium phosphate, or uric acid.
由磷酸钙或者尿酸造成的肾结石则不太常见。
A slightly different type of stone made of the minerals magnesium ammonium phosphate,
另一种稍有不同的结石是由磷酸铵镁构成的，
or struvite, can be caused by bacterial infection.
也叫鸟粪石，细菌感染是此类肾结石产生的罪魁祸首。
And even rarer stones can result from genetic disorders or certain medications.
除此之外，更为罕见的肾结石由遗传疾病或是某些特殊的药物造成。
A kidney stone can go undetected until it starts to move.
肾结石可能在它开始移动后才会被检测出来。
When a stone travels through the kidney and into the ureter, its sharp edges scratch the walls of the urinary tract.
当结石从肾脏移动到尿管里的时候，它尖利的边缘会擦伤尿道壁。
Nerve endings embedded in this tissue transmit excruciating pain signals through the nervous system.
薄壁中包裹着的神经末梢会通过神经系统输送剧烈疼痛的信号。
And the scratches can send blood flowing into the urine.
此外，擦伤还会导致血液进入尿液。
This can be accompanied by symptoms of nausea, vomiting, and a burning sensation while urinating.
这会造成血尿并常伴随着恶心、呕吐、排尿有烧灼感等症状。
If a stone gets big enough to actually block the flow of urine,
当结石长大到直接堵塞了尿液流通，
it can create an infection, or back flow, and damage the kidneys themselves.
就会出现尿路感染或者尿液倒流的症状，并对肾脏自身造成伤害。
But most kidney stones don't become this serious, or even require invasive treatment.
但是大多数肾结石不会变得这么严重，甚至到需要进行手术的程度。
Masses less than five millimeters in diameter will usually pass out of the body on their own.
那些直径不超过五毫米的结石通常能自行排出。

A doctor will often simply recommend drinking large amounts of water
医生通常会建议病人多喝水
to help speed the process along, and maybe taking some pain killers.
以加快结石的排出，或服用止痛片来缓解疼痛。
If the stone is slightly larger, medications like alpha blockers
如果结石稍微有点大，就需要药物的帮助，比如受体阻断剂，
can help by relaxing the muscles in the ureter and making it easier for the stone to get through.
它可以帮助松弛尿道输尿管的肌肉，使结石更顺利地通过。
Another medication called potassium citrate can help dissolve the stones by creating a less acidic urine.
另外一种药物叫做柠檬酸钾，它可以通过降低尿液酸性来帮助溶解结石。
For medium-sized stones up to about ten millimeters, one option is pulverizing them with soundwaves.
对于不超过十毫米的中等结石，可以选择用声波将其碾碎。
Extracorporeal shock wave lithotripsy uses high-intensity pulses of focused ultrasonic energy aimed directly at the stone.
体外震波碎石术通过超声波产生高强度冲击波聚焦后直接对准体内的结石。
The pulses create vibrations inside the stone itself and small bubbles jostle it.
冲击波会在结石内部产生震动，以及受挤压的微气泡。
These combined forces crush the stone into smaller pieces that can pass out of the body more easily.
这些力量合在一起能够将结石击碎，从而更易于排出。
But zapping a stone with sound doesn't work as well if it's simply too big.
但是如果结石的尺寸过大，使用声波碎石的方法就可能不起作用。
So sometimes, more invasive treatments are necessary.
这时候就需要进行侵入性治疗。
A rigid tube called a stent can be placed in the ureter to expand it.
比如放置硬质管道支架来扩张尿道。
Optical fibers can deliver laser pulses to break up the stone.
光纤可以输送激光脉冲来打碎结石。
Stones can also be surgically removed through an incision in the patient's back or groin.
此外，还可以在病人的后背或腹股沟制造切口，伸入手术用具，使结石通过手术被取出。
What about just avoiding kidney stones in the first place?
那么如何在肾结石产生前就加以预防呢？
For people prone to them, their doctor may recommend drinking plenty of water,
对容易产生结石的人们来说，医生会建议他们大量喝水，
which dilutes the calcium oxalate and other compounds that eventually build up into painful stones.
稀释体内的草酸钙，以及其他会产生痛苦的结石的物质。
Foods like potato chips, spinach, rhubarb, and beets are high in oxalate, so doctors might advise limiting them.
有些食物，比如薯片，菠菜，大黄，还有甜菜，都是草酸含量很高的，所以医生建议控制这类食物的摄入。
Even though calcium is often found in stones, calcium in foods and beverages can actually help
虽然钙是结石的常见成分，但食物和饮料里的钙其实有助于预防肾结石，
by binding to oxalate in the digestive tract before it can be absorbed and reach the kidneys.
这是因为它们会和消化道里的草酸结合，使其无法直接被吸收并进入肾脏。
If you do end up with a kidney stone, you're not alone.
如果你已经有了肾结石，也不要感到孤单无助。
Data suggests that rates are rising, but that world record probably won't be broken any time soon.
数据表明肾结石的发病率一直在升高，当然，世界最大肾结石的记录在短时间内应该还是不会被打破。