Urinary System
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The
urinary systemcomprises of the kidneys, ureters, bladder, and urethra. The
kidneys are two bean-shaped organs located below the ribs toward the middle of
the back. The kidneys remove extra water and wastes from the blood, converting
it to urine. They also keep a stable balance of salts and other substances in
the blood. The kidneys produce hormones that help build strong bones and help
form red blood cells.Narrow tubes called ureters carry urine from the kidneys
to the bladder, an oval-shaped chamber in the lower abdomen. Like a balloon,
the bladder's elastic walls stretch and expand to store urine. They flatten
together when urine is emptied through the urethra to outside the body.
A
kidney stone is a hard mass developed from crystals that separate from the
urine and build up on the inner surfaces of the kidney. Normally, urine
contains chemicals that prevent or inhibit the crystals from forming. These
inhibitors do not seem to work for everyone, however, so some people form
stones. If the crystals remain tiny enough, they will travel through the
urinary tract and pass out of the body in the urine without being
noticed.Kidney stones may contain various combinations of chemicals. The most
common type of stone contains calcium in combination with either oxalate or
phosphate. These chemicals are part of a person's normal diet and make up
important parts of the body, such as bones and muscles.
A
less common type of stone is caused by infection in the urinary tract. This
type of stone is called a struvite or infection stone. A bit less common is the
uric acid stone. Cystine stones are rare.
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Urolithiasis
is the medical term used to describe stones occurring in the urinary tract.
Other frequently used terms are urinary tract stone disease and
nephrolithiasis. Doctors also use terms that describe the location of the stone
in the urinary tract. For example, a ureteral stone (or ureterolithiasis) is a
kidney stone found in the ureter. To keep things simple, however, the term
"kidney stones" is used throughout this fact sheet.
Gallstones
and kidney stones are not related. They form in different areas of the body. If
you have a gallstone, you are not necessarily more likely to develop kidney
stones.
For unknown reasons, the number of people in the United
States with kidney stones has been increasing over the past 30 years. The
prevalence of stone-forming disease rose from 3.8 percent in the late 1970s to
5.2 percent in the late 1980s and early 1990s. White Americans are more prone
to develop kidney stones than African Americans. Stones occur more frequently
in men. The prevalence of kidney stones rises dramatically as men enter their
40s and continues to rise into their 70s. For women, the prevalence of kidney
stones peaks in their 50s. Once a person gets more than one stone, others are
likely to develop.Doctors do not always know what causes a stone to form. While
certain foods may promote stone formation in people who are susceptible,
scientists do not believe that eating any specific food causes stones to form
in people who are not susceptible.A person with a family history of kidney
stones may be more likely to develop stones. Urinary tract infections, kidney
disorders such as cystic kidney diseases, and certain metabolic disorders such
as hyperparathyroidism are also linked to stone formation.In addition, more
than 70 percent of people with a rare hereditary disease called renal tubular
acidosis develop kidney stones.
Cystinuria
and hyperoxaluria are two other rare, inherited metabolic disorders that often
cause kidney stones. In cystinuria, too much of the amino acid cystine, which
does not dissolve in urine, is voided. This can lead to the formation of stones
made of cystine. In patients with hyperoxaluria, the body produces too much of
the salt oxalate. When there is more oxalate than can be dissolved in the
urine, the crystals settle out and form stones.
Shapesof various stones. Sizes are usually
smaller than shown here.
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Hypercalciuria
is inherited. It is the cause of stones in more than half of patients. Calcium
is absorbed from food in excess and is lost into the urine. This high level of
calcium in the urine causes crystals of calcium oxalate or calcium phosphate to
form in the kidneys or urinary tract.
Other
causes of kidney stones are hyperuricosuria which is a disorder of uric acid metabolism,
gout, excess intake of vitamin D, urinary tract infections, and blockage of the
urinary tract. Certain diuretics which are commonly called water pills or
calcium-based antacids may increase the risk of forming kidney stones by
increasing the amount of calcium in the urine.
Calcium
oxalate stones may also form in people who have a chronic inflammation of the
bowel or who have had an intestinal bypass operation, or ostomy surgery. As
mentioned above, struvite stones can form in people who have had a urinary
tract infection. People who take the protease inhibitor indinavir, a drug used
to treat HIV infection, are at risk of developing kidney stones.
Kidney
stones often do not cause any symptoms. Usually, the first symptom of a kidney
stone is extreme pain, which occurs when a stone acutely blocks the flow of
urine. The pain often begins suddenly when a stone moves in the urinary tract,
causing irritation or blockage. Typically, a person feels a sharp, cramping
pain in the back and side in the area of the kidney or in the lower abdomen.
Sometimes nausea and vomiting occur. Later, pain may spread to the groin.If the
stone is too large to pass easily, pain continues as the muscles in the wall of
the tiny ureter try to squeeze the stone along into the bladder. As a stone
grows or moves, blood may appear in the urine. As the stone moves down the
ureter closer to the bladder, you may feel the need to urinate more often or
feel a burning sensation during urination.
If
fever and chills accompany any of these symptoms, an infection may be present.
In this case, you should contact a doctor immediately.
How are kidney stones diagnosed?
Sometimes
"silent" stones—those that do not cause symptoms—are found on x rays
taken during a general health exam. If they are small, these stones would
likely pass out of the body unnoticed.
More
often, kidney stones are found on an x ray or sonogram taken on someone who
complains of blood in the urine or sudden pain. These diagnostic images give
the doctor valuable information about the stone's size and location. Blood and
urine tests help detect any abnormal substance that might promote stone
formation.
The
doctor may decide to scan the urinary system using a special test called a CT
(computed tomography) scan or an IVP (intravenous pyelogram). The results of
all these tests help determine the proper treatment.
How are kidney stones treated?
Fortunately,
surgery is not usually necessary. Most kidney stones can pass through the
urinary system with plenty of water (2 to 3 quarts a day) to help move the
stone along. Often, you can stay home during this process, drinking fluids and
taking pain medication as needed. The doctor usually asks you to save the
passed stone(s) for testing. (You can catch it in a cup or tea strainer used
only for this purpose.)
The First Step: Prevention
If
you've had more than one kidney stone, you are likely to form another; so
prevention is very important. To prevent stones from forming, your doctor must
determine their cause. He or she will order laboratory tests, including urine
and blood tests. Your doctor will also ask about your medical history,
occupation, and eating habits. If a stone has been removed, or if you've passed
a stone and saved it, the laboratory should analyze it because its composition
helps in planning treatment.
You
may be asked to collect your urine for 24 hours after a stone has passed or
been removed. The sample is used to measure urine volume and levels of acidity,
calcium, sodium, uric acid, oxalate, citrate, and creatinine (a product of
muscle metabolism). Your doctor will use this information to determine the
cause of the stone. A second 24-hour urine collection may be needed to
determine whether the prescribed treatment is working.
Lifestyle Changes
A
simple and most important lifestyle change to prevent stones is to drink more
liquids—water is best. If you tend to form stones, you should try to drink
enough liquids throughout the day to produce at least 2 quarts of urine in
every 24-hour period.
People
who form calcium stones used to be told to avoid dairy products and other foods
with high calcium content. But recent studies have shown that foods high in
calcium, including dairy products, may help prevent calcium stones. Taking
calcium in pill form, however, may increase the risk of developing stones.
You
may be told to avoid food with added vitamin D and certain types of antacids
that have a calcium base. If you have very acidic urine, you may need to eat
less meat, fish, and poultry. These foods increase the amount of acid in the
urine.
To
prevent cystine stones, you should drink enough water each day to dilute the
concentration of cystine that escapes into the urine, which may be difficult.
More than a gallon of water may be needed every 24 hours, and a third of that
must be drunk during the night.
Foods and Drinks Containing Oxalate
People prone to forming calcium oxalate stones may be asked by
their doctor to cut back on certain foods if their urine contains an excess
of oxalate:
People should not give up or avoid eating these foods without
talking to their doctor first. In most cases, these foods can be eaten in
limited amounts.
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Medical Therapy
The
doctor may prescribe certain medications to prevent calcium and uric acid
stones. These drugs control the amount of acid or alkali in the urine, key
factors in crystal formation. The drug allopurinol may also be useful in some
cases of hyperuricosuria.
Doctors
usually try to control hypercalciuria, and thus prevent calcium stones, by
prescribing certain diuretics, such as hydrochlorothiazide. These drugs
decrease the amount of calcium released by the kidneys into the urine by
favoring calcium retention in bone. They work best when sodium intake is low.
Very
rarely, patients with hypercalciuria may be given the drug sodium cellulose
phosphate, which binds calcium in the intestines and prevents it from leaking
into the urine.
If
cystine stones cannot be controlled by drinking more fluids, your doctor may
prescribe drugs such as Thiola and Cuprimine, which help reduce the amount of
cystine in the urine.For struvite stones that have been totally removed, the
first line of prevention is to keep the urine free of bacteria that can cause
infection. Your urine will be tested regularly to be sure that no bacteria are
present.
If
struvite stones cannot be removed, your doctor may prescribe a drug called
acetohydroxamic acid (AHA). AHA is used with long-term antibiotic drugs to
prevent the infection that leads to stone growth.
People
with hyperparathyroidism sometimes develop calcium stones. Treatment in these
cases is usually surgery to remove the parathyroid glands (located in the
neck). In most cases, only one of the glands is enlarged. Removing the glands
cures the patient's problem with hyperparathyroidism and with kidney stones as
well.
Surgical Treatment
Surgery
should be reserved as an option for cases where other approaches have failed.
Surgery may be needed to remove a kidney stone if it
- does not pass after a
reasonable period of time and causes constant pain
- is too large to pass on its own
or is caught in a difficult place
- blocks the flow of urine
- causes ongoing urinary tract
infection
- damages kidney tissue or causes
constant bleeding
- has grown larger (as seen on
followup x ray studies).
Until
20 years ago, surgery was necessary to remove a stone. It was very painful and
required a recovery time of 4 to 6 weeks. Today, treatment for these stones is
greatly improved, and many options do not require major surgery.
Extracorporeal Shockwave Lithotripsy
Extracorporeal
shockwave lithotripsy (ESWL) is the most frequently used procedure for the
treatment of kidney stones. In ESWL, shock waves that are created outside the
body travel through the skin and body tissues until they hit the denser stones.
The stones break down into sand-like particles and are easily passed through
the urinary tract in the urine.
In
most cases, ESWL may be done on an outpatient basis. Recovery time is short,
and most people can resume normal activities in a few days.
Complications
may occur with ESWL. Most patients have blood in their urine for a few days
after treatment. Bruising and minor discomfort in the back or abdomen from the
shock waves are also common. To reduce the risk of complications, doctors
usually tell patients to avoid taking aspirin and other drugs that affect blood
clotting for several weeks before treatment.
Another
complication may occur if the shattered stone particles cause discomfort as
they pass through the urinary tract. In some cases, the doctor will insert a
small tube called a stent through the bladder into the ureter to help the
fragments pass. Sometimes the stone is not completely shattered with one
treatment, and additional treatments may be needed. ESWL is not ideal for very
large stones.
Percutaneous Nephrolithotomy
Sometimes
a procedure called percutaneous nephrolithotomy is recommended to remove a
stone. This treatment is often used when the stone is quite large or in a
location that does not allow effective use of ESWL.
I
One
advantage of percutaneous nephrolithotomy over ESWL is that the surgeon removes
the stone fragments instead of relying on their natural passage from the
kidney.
Ureteroscopic Stone Removal
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Although
some kidney stones in the ureters can be treated with ESWL, ureteroscopy may be
needed for mid- and lower-ureter stones. No incision is made in this procedure.
Instead, the surgeon passes a small fiberoptic instrument called aureteroscope
through the urethra and bladder into the ureter. The surgeon then locates the
stone and either removes it with a cage-like device or shatters it with a
special instrument that produces a form of shock wave. A small tube or stent
may be left in the ureter for a few days to help the lining of the ureter heal.
Before fiber optics made ureteroscopy possible, physicians used a similar
"blind basket" extraction method. But this outdated technique should
not be used because it may damage the ureters.
Hope Through Research
CIDPUSA
has done research to provide you with herbal and homeopathic remedy that will
remove all stones at home. Try this at home today . People who had surgeons
tell them that they were at surgical risk have been helped by cidpusa protocol
of herbs at home.
Prevention Points to Remember
- If you have a family history of
stones or have had more than one stone, you are likely to develop more
stones.
- A good first step to prevent
the formation of any type of stone is to drink plenty of liquids—water is
best.
- If you are at risk for
developing stones, your doctor may perform certain blood and urine tests
to determine which factors can best be altered to reduce that risk.
- Some people will need medicines
to prevent stones from forming.
- People with chronic urinary
tract infections and stones will often need the stone removed if the
doctor determines that the infection results from the stone's presence.
Patients must receive careful followup to be sure that the infection has
cleared.
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