Kidney stones are made of salts and minerals in the urine that stick together to form small “pebbles.” They are usually painless while they remain in the kidney, but they can cause severe pain as they travel through the ureters (narrow tubes that connect the kidneys and the bladder) to exit the body during urination.

There are four main types of kidney stones, and they can be as small as grains of sand or as large as a golf ball. Kidney stones occur most often in adults and are rare in children.

Kidney stones may form when the normal balance of water, salts, minerals, and other substances found in urine changes. How this balance changes determines the type of kidney stone you have. Most kidney stones are calcium-type. They form when the calcium levels in your urine change.

Factors that change your urine balance include:

●Not drinking enough water. When you don't drink enough water, the salts, minerals, and other substances in the urine can stick together and form a stone. This is the most common cause of kidney stones.

●Medical conditions. Many medical conditions can affect the normal balance and cause stones to form. Examples include gout and inflammatory bowel disease, such as Crohn's disease.

More commonly, kidney stones can run in families, as stones often occur in family members over several generations.

In rare cases, a person forms kidney stones because the parathyroid glands produce too much of a hormone, which leads to higher calcium levels and possibly calcium kidney stones.

Kidney stones form in the kidney. If they stay in the kidney, they typically do not cause pain. When they travel out of the body through the tubes of the urinary tract (including the ureters, which connect the kidney to the bladder, or the urethra, which leads outside the body), their movement may cause:

●No symptoms, if the stone is small enough.

●Sudden, severe pain that gets worse in waves. Stones may cause intense pain in the back, side, abdomen, groin, or genitals. People who have had a kidney stone often describe the pain as “the worst pain I've ever had.”

●Feeling sick to the stomach (nausea) and vomiting.

●Blood in the urine (hematuria), which can occur either with stones that stay in the kidney or with those that travel through the ureters.

●Frequent and painful urination, which may occur when the stone is in the ureter or after the stone has left the bladder and is in the urethra. Painful urination may occur when a urinary tract infection is also present.

●Conditions with similar symptoms include appendicitis, hernias, ectopic pregnancy, and prostatitis.

The patient's first diagnosis of kidney stones often occurs when he see the doctor or go to an emergency room because he is in great pain. The doctor or an emergency medicine specialist will ask the patient questions and examine him. After the patient passes a stone, the doctor may give him another exam to find out whether he is likely to get kidney stones again.

The doctor may do one or more of the following tests to help diagnose kidney stones, see where the stones are located, and find out if they are causing or may cause damage to the urinary tract

●A noncontrast spiral computed tomography (CT) scan is the preferred test for kidney stones. It is a special type of CT scan that moves in a circle.

●An intravenous pyelogram (IVP) is an X-ray test that can show the size, shape, and position of the urinary tract, including the kidneys and ureters. See an IVP of a kidney stone

●A retrograde pyelogram may be done if the IVP or CT scan does not provide a diagnosis.

●Urinalysis and urine cultures test your urine. An abdominal X-ray (KUB) gives a picture of the kidneys, the bladder, and the tubes that connect the kidneys to the bladder (ureters).

●An ultrasound exam of the kidneys (ultrasonogram) is the preferred test for pregnant women.

Determining the type of the patient's kidney stone will help with treatment decisions and measures to prevent stones from forming again. Tests include:

●A medical history and physical exam.

●Stone analysis.

●Blood chemistry screen, to measure kidney function, levels of calcium, uric acid, phosphorus, electrolytes, and other substances that may have caused the stone to form.

●Urine collection for 24 hours, to measure volume, pH, calcium, oxalate, uric acid, and other substances that may have caused the stone to form. This is a test the patient may do at home.

For small stones, most people don't need any treatment other than taking pain medicine and drinking enough fluids.

If the doctor thinks the stone can pass on its own, and if you feel you can deal with the pain, he or she may suggest home treatment, including:

●Using pain medicine. Nonprescription medicine, such as nonsteroidal antiinflammatory drugs (NSAIDs), may relieve your pain. Your doctor can prescribe stronger pain medicine if needed.

●Drinking enough fluids. You'll need to keep drinking water and other fluids when you are passing a kidney stone.

The doctor may prescribe medicine to help your body pass the stone. To learn more, see Medications.

If your pain is too severe, if the stones are blocking the urinary tract, or if you also have an infection, your doctor will probably suggest a medical procedure, such as lithotripsy, or surgery to deal with the stone.

Medicine you can buy without a prescription, such as nonsteroidal anti-inflammatory drugs (NSAIDs), may relieve your pain while you pass a stone.

Your doctor may also prescribe medicine to help your body pass the stone. Alphablockers have been shown to help kidney stones pass more quickly with very few side effects. Ask your doctor if these medicines can help you.

Which medicine you take depends on the type of stones you have.

Calcium stones are the most common kind ofkidney stone. To prevent them, you may take:

●Thiazides.

●Potassium citrate.

●Orthophosphate.

About 5 to 10 out of 100 kidney stones are made of uric acid, a waste product that normally exits the body in the urine. To prevent these types of stones, you may take:

●Potassium citrate.

●Sodium bicarbonate.

●Allopurinol.

A very small number of stones are made of a chemical called cystine. Medicines to prevent them include:

●Potassium citrate.

●Penicillamine.

●Tiopronin.

●Captopril.

Some struvite stones (staghorn calculi) form because of frequent kidney infections. If you have a struvite stone, you will most likely need antibiotics to cure the infection and help prevent new stones from forming. You may need surgery to remove the stone. Urease inhibitors may be used to prevent struvite stones.

Surgery is rarely needed to treat kidney stones. Surgery is only needed when the kidney stone is very large, caused by an infection (staghorn calculi), blocking the flow of urine out of the kidney, or causing other problems like severe bleeding.

●In percutaneous nephrolithotomy or nephrolithotripsy, the surgeon makes a small cut in your back. He or she then puts a hollow tube into your kidney and either removes (lithotomy) or breaks up and removes (lithotripsy) the stone. This surgery may be used if other procedures do not work or if you have a very large stone. See a picture of nephrolithotomy.

●In open surgery, the surgeon makes a cut in your side or stomach to reach the kidneys. He or she removes the stone.

If your kidney stones were caused by a problem with your parathyroid gland, your doctor may suggest surgery to remove a parathyroid gland or glands (parathyroidectomy). This can help prevent future kidney stones.

Other treatments for kidney stones are much more common than surgery. You may need one of these treatments if your pain is very bad, your stone is blocking the urinary tract, or you have an infection. Your options include:

●Extracorporeal shock wave lithotripsy (ESWL). ESWL uses shock waves that pass easily through the body but are strong enough to break up a kidney stone. This is the most commonly used medical procedure for treating kidney stones. See a picture of ESWL

●Ureteroscopy. The surgeon passes a very thin viewing tool (ureteroscope) up the urinary tract to the stone's location, and then he or she uses tools to remove the stone or break it up for easier removal. You may need a small, hollow tube (ureteral stent) placed in the ureter to keep it open for a short time and drain urine and any stone pieces. This procedure is often used for stones that have moved from the kidney to the ureter. See a picture of ureteroscopy

Whether these treatments will work for you will depend on the size of the stone, its location in the urinary tract, and your overall health.

After you have had kidney stones, you are more likely to have them again. You can help prevent them by drinking plenty of water, enough so that your urine is light yellow or clear like water, about 8 to 10 glasses of water a day. You may have to eat less of certain foods. Your doctor may also give you medicine that helps prevent stones from forming.

allopurinol [,ælə(ʊ)'pjʊərinɒl] n.别嘌呤醇

appendicitis [ə,pɛndə'saitis] n.阑尾炎

captopril ['kæptəpril] n.甲巯丙脯酸

dehydrated [,diː'haidreitid] adj.脱水的

electrolytes [i'lektrə,laits] n.电解质

gauze [gɔz] n.纱布；薄纱

gout [gaʊt] n.痛风

groin [grɔin] n.腹股沟

hernia ['hɜːniə] n. 疝气

lithotripsy ['liθə,tripsi] n.碎石术

nephrolithotomy [,nefrəuli'θɔtəmi] n.肾切开取结石术

oxalate ['ɑksə,let] n.草酸；草酸盐

orthophosphate [,ɔːθəʊ'fɒsfeit] n.正磷酸盐

parathyroidectomy [,pærə,θairɔi'dɛktəmi] n.甲状旁腺切除术

pebble ['pɛbl] n.卵石

penicillamine [,pɛni'silə,min] n.青霉胺

phosphorus ['fɑsfərəs] n.磷

ureteroscope [jʊəriːtə'rəskəʊp] n.输尿管镜

ureteroscopy [jʊəriːtə'rəskəpi] n.输尿管镜检查术

abdominal X-ray (KUB) 腹部平片

alpha-blocker α-受体阻滞剂

Crohn's disease 克罗恩病

calcium stone 含钙结石

cystine stone 胱氨酸结石

ectopic pregnancy 宫外孕

extracorporeal shock wave lithotripsy (ESWL) 体外冲击波碎石术

inflammatory bowel disease 炎症性肠病

nonsteroidal anti-inflammatory drugs (NSAIDs) 非甾体类抗炎药

parathyroid glands 甲状旁腺

potassium citrate 柠檬酸钾

percutaneous nephrolithotomy 经皮肾镜取石术

retrograde pyelogram 逆行肾盂造影

rib cage 胸腔

sodium bicarbonate 碳酸氢钠

struvite stone 感染性结石

staghorn calculi 鹿角形结石

uric acid stone 尿酸结石