Kidney Stones

What is a kidney stone?

A
kidney stone is a hard, pebble-like deposit that forms in the kidney. -Most are as small
as a grain of sand or as large as a pearl. Rarely, they can be as big as golf balls. A
stone may be smooth, irregular in shape, or jagged. Most are yellow or brown in color.
There are different types of kidney stones:

  • Calcium
    stones.
    Calcium stones are the most common type of stones. Calcium is a
    normal part of a healthy diet and is used by bones and muscles. Calcium not used by
    the body goes to the kidneys where it is normally flushed out with the urine. In some
    people, the calcium that stays behind bonds with other waste products to form a
    stone.
  • Struvite
    stones.
    Struvite stones contain the mineral magnesium and the waste product
    ammonia. It may form after an infection in the urinary tract.
  • Uric acid
    stones.
    Uric acid stones may form when there is too much acid in the urine.
    This can be seen in people who have gout.
  • Cysteine
    stones.
    Ceystine is one of the building blocks that make up muscles, nerves,
    and other parts of the body. It can build up in the urine and form a stone. Cysteine
    stones are rare. This form of the disease runs in families.

Kidney stones are one of the most painful disorders. They are also one of the most
common problems of the urinary tract.

What causes a kidney stone?

A kidney stone develops from crystals
that build up in the kidney. Urine normally contains chemicals that prevent or slow the
crystals from forming. But stones still form in some people. Small crystals can travel
through the urinary tract and pass out of the body in the urine without even being
noticed. A larger stone can get stuck in a ureter. The ureter is the small tube between
the kidney and the bladder. A large stone can also get stuck in the bladder or the
urethra. The urethra is the tube from the bladder that takes urine out of the body. A
large stone may block the flow of urine and cause great pain.

Who is at risk for kidney stones?

You are more likely to get a kidney stone if you:

  • Are white. Whites are at higher risk than African Americans
  • Are male. Kidney stones happen more often in men, but the number of women who get
    kidney stones has been growing.
  • Are age 20 to 40.
  • Have had a stone in the past. Once you’ve had one stone, you are more likely to
    get more.

These are factors you can control:

  • How
    much fluid you drink. If you don’t drink enough fluids and tend to be dehydrated, you
    are at a higher risk for kidney stones.
  • Your
    diet. Eating a diet that is high in protein, sodium, and dark green vegetables
    (oxalate-rich types of foods), can increase your risk for kidney stones.
  • Your
    weight. Being overweight increases insulin resistance in your body. Insulin
    resistance increases the amount of calcium filtered into the urine. In turn, this
    increases the risk of developing a kidney stone.
  • Medicines. Some medicines can increase your risk for kidney stones. Common medicines
    include water pills (diuretics) and antiviral medicines.

These things you can’t control:

  • Certain
    diseases. Diseases that cause ongoing higher levels of calcium in the blood. More
    calcium can cause dehydration because you make more urine. The extra calcium in the
    kidney solidifies into a stone.
  • Surgery. Surgeries on the digestive tract including the intestines and gastric
    bypass can make you more likely to have long-term (chronic) dehydration. Or you may
    develop diseases that cause chronic diarrhea and dehydration. These increase the risk
    for kidney stones.
  • Family
    history. Inherited factors or a family history of kidney stones can raise your
    risk.
  • Past
    urinary tract infections that kept returning
  • Low
    estrogen. Women with low estrogen levels after menopause or after removal of the
    ovaries are at greater risk for kidney stones.
  • Gender.
    Men between the ages of 30 and 50 are the most likely to get kidney stones.
  • High
    uric acid level. Diseases that raise uric acid levels (gout) raise your risk for
    stones.
  • Diabetes. Insulin resistance from diabetes can cause an increase the amount of
    calcium filtered into the urine. This raises the risk for a kidney stone.

What are the symptoms of kidney stones?

These are the most common symptoms of kidney stones:

  • Extreme, sharp pain in the back or side that will not go away. Changing positions
    doesn’t help. Pain can come and go.
  • Blood in
    the urine
  • Nausea
    and vomiting
  • Cloudy
    or odorous urine
  • Frequent urination
  • A
    burning feeling when you urinate
  • Fever
    and chills

The
symptoms of kidney stones may look like other health problems. Always talk with
your healthcare provider for a diagnosis.

How are kidney stones diagnosed?

Your
healthcare provider will ask about your health history and do a physical exam. You may
have other tests. These include:

  • Intravenous
    pyelogram (IVP). 
    This is a series of X-rays of the kidney, ureters, and
    bladder with the injection of a contrast dye into the vein. It helps find tumors,
    kidney stones, or blockages. It can also check blood flow to the kidney.
  • CT
    scan. 
    This is an imaging test that uses X-rays and a computer to make
    detailed images of the body. A CT scan shows details of the bones, muscles, fat, and
    organs.
  • Urinalysis. This is a lab exam of urine for various cells and chemicals,
    such as red blood cells, white blood cells, infection, or extra protein.
  • Blood
    tests. 
    These are lab exams of the blood to look for substances that might
    cause stone to form. These tests can also assess how well your kidneys are
    working.
  • Renal
    ultrasound. 
    A noninvasive test in which sound waves are bounced off the
    kidney. The test sends a picture of the kidney to a video screen. The test is used to
    find the size and shape of the kidney. It can also see a mass, kidney stone, cyst, or
    other blockage in the kidney.