What’s a kidney stone?

A stone in your kidney is an irregularly-shaped solid mass or crystal that

can be as small as a grain of sand up to the size of a golf ball. Depending
on the size of your kidney stone (or stones), you may not even realize
that you have one. Even small stones can cause extreme pain as they
exit your body through your urinary tract. Drinking fluids may help the
process, which can take as long as three weeks.

A large kidney stone can get trapped in your ureter (the tube that drains
urine from your kidney down to your bladder). When this happens, the
stone can cause bleeding and keep urine from leaving your body. You
may need surgery for a stone that can’t pass on its own.

Symptoms

You can have a stone in your kidney for years and not know it’s there.
But, when it starts to move or becomes very large, you may have
symptoms. Symptoms of a kidney stone include:

 Feeling pain in your lower back or side of your body. This pain can
start as a dull ache that may come and go. It can also become
severe and result in a trip to the emergency room.
 Having nausea and/or vomiting with the pain.
 Seeing blood in your urine.
 Feeling pain when urinating.
 Being unable to urinate.
 Feeling the need to urinate more often.
 Fever or chills.
 Having urine that smells bad or looks cloudy.

Smaller kidney stones may not cause pain or other symptoms. These
“silent stones” pass out of your body in your urine.

Symptoms in children

The most common symptoms of kidney stones are blood in the urine or
pain. The amount of pain your child experiences and where it hurts
depends on where the stone is located and its size. Other symptoms
include:

 Severe colicky pain.

 Inability to urinate (when a stone blocks the urinary tract).
 Nausea/vomiting.
 Cloudy, foul-smelling urine, fever, chills or weakness which might
be a sign of a serious infection.
 Blood in the urine.

Causes
Kidney stones often have no definite, single cause, although several factors may
increase your risk.
Kidney stones form when your urine contains more crystal-forming substances —
such as calcium, oxalate and uric acid — than the fluid in your urine can dilute. At the
same time, your urine may lack substances that prevent crystals from sticking
together, creating an ideal environment for kidney stones to form.
Types
Knowing the type of kidney stone you have helps determine its cause, and may give
clues on how to reduce your risk of getting more kidney stones. If possible, try to
save your kidney stone if you pass one so that you can bring it to your doctor for
analysis.
Types of kidney stones include:
 Calcium stones. Most kidney stones are calcium stones, usually in the
form of calcium oxalate. Oxalate is a substance made daily by your liver
or absorbed from your diet. Certain fruits and vegetables, as well as nuts
and chocolate, have high oxalate content.
Dietary factors, high doses of vitamin D, intestinal bypass surgery and
several metabolic disorders can increase the concentration of calcium or
oxalate in urine.
Calcium stones may also occur in the form of calcium phosphate. This
type of stone is more common in metabolic conditions, such as renal
tubular acidosis. It may also be associated with certain medications
used to treat migraines or seizures, such as topiramate (Topamax,
Trokendi XR, Qudexy XR).

 Struvite stones. Struvite stones form in response to a urinary tract infection.

These stones can grow quickly and become quite large, sometimes with few
symptoms or little warning.

 Uric acid stones. Uric acid stones can form in people who lose too much fluid
because of chronic diarrhea or malabsorption, those who eat a high-protein diet,
 and those with diabetes or metabolic syndrome. Certain genetic factors also
may increase your risk of uric acid stones.

 Cystine stones. These stones form in people with a hereditary disorder called
cystinuria that causes the kidneys to excrete too much of a specific amino acid.

Risk factors
Factors that increase your risk of developing kidney stones include:

 Family or personal history. If someone in your family has had kidney stones,
you're more likely to develop stones, too. If you've already had one or more
kidney stones, you're at increased risk of developing another.

 Dehydration. Not drinking enough water each day can increase your risk of
kidney stones. People who live in warm, dry climates and those who sweat a lot
may be at higher risk than others.

 Certain diets. Eating a diet that's high in protein, sodium (salt) and sugar may
increase your risk of some types of kidney stones. This is especially true with a
high-sodium diet. Too much salt in your diet increases the amount of calcium
your kidneys must filter and significantly increases your risk of kidney stones.

 Obesity. High body mass index (BMI), large waist size and weight gain have
been linked to an increased risk of kidney stones.

 Digestive diseases and surgery. Gastric bypass surgery, inflammatory bowel

disease or chronic diarrhea can cause changes in the digestive process that
affect your absorption of calcium and water, increasing the amounts of stone-
forming substances in your urine.

 Other medical conditions such as renal tubular acidosis, cystinuria,

hyperparathyroidism and repeated urinary tract infections also can increase
your risk of kidney stones.

 Certain supplements and medications, such as vitamin C, dietary supplements,

laxatives (when used excessively), calcium-based antacids, and certain
medications used to treat migraines or depression, can increase your risk of
kidney stones.

Diet Recommendations for Kidney Stones

General Recommendations
1. Drink plenty of fluid: 2-3 quarts/day
o This includes any type of fluid such as water, coffee and lemonade which
have been shown to have a beneficial effect with the exception of grapefruit
juice and soda.
o This will help produce less concentrated urine and ensure a good urine
 volume of at least 2.5L/day
2. Limit foods with high oxalate content
o Spinach, many berries, chocolate, wheat bran, nuts, beets, tea and rhubarb
should be eliminated from your diet intake
3. Eat enough dietary calcium
o Three servings of dairy per day will help lower the risk of calcium stone
formation. Eat with meals.
4. Avoid extra calcium supplements
o Calcium supplements should be individualized by your physician and
registered kidney dietitian
5. Eat a moderate amount of protein
o High protein intakes will cause the kidneys to excrete more calcium therefore
this may cause more stones to form in the kidney
6. Avoid high salt intake
o High sodium intake increases calcium in the urine which increases the
chances of developing stones
o Low salt diet is also important to control blood pressure.
7. Avoid high doses of vitamin C supplements
o It is recommend to take 60mg/day of vitamin C based on the US Dietary
Reference Intake
o Excess amounts of 1000mg/day or more may produce more oxalate in the
body

Tips for a kidney stone diet

Having kidney stones increases your risk of getting them again unless you
actively work to prevent them. This means taking medications prescribed to
you for this purpose, and watching what you eat and drink.

If you currently have stones, your doctor will run diagnostic tests, to determine
what type you have. They will then prescribe a specific diet plan for you, such
as the DASH Diet. Tips that will help include:

 drink at least twelve glasses of water daily

 eat citrus fruits, such as orange

 eat a calcium-rich food at each meal, at least three times a day

 limit your intake of animal protein

 eat less salt, added sugar, and products containing high fructose corn
syrup

 avoid foods and drinks high in oxalates and phosphates

  avoid eating or drinking anything which dehydrates you, such as alcohol.

What to eat and drink

If you’re trying to avoid kidney stones, what you eat and drink is as important
as what you shouldn’t eat and drink. Here are some important rules of thumb
to keep in mind.

Stay hydrated

Fluids, especially water, help to dilute the chemicals that form stones. Try to
drink at least 12 glasses of water a day.

Up your citrus intake

Citrus fruit, and their juice, can help reduce or block the formation of stones
due to naturally occurring citrate. Good sources of citrus include lemons,
oranges, and grapefruit.

Eat lots of calcium (and vitamin D)

If your calcium intake is low, oxalate levels may rise. It’s preferable to get your
calcium from food, rather than from supplements, as these have been linked
to kidney stone formation. Good sources of calcium include milk, yogurt,
cottage cheese, and other types of cheeses. Vegetarian sources of calcium
include legumes, calcium-set tofu, dark green vegetables, nuts, seeds, and
blackstrap molasses. If you don’t like the taste of cow’s milk, or, if it doesn’t
agree with you, try lactose-free milk, fortified soy milk, or goat’s milk. Also
make sure to include foods high in vitamin D each day. Vitamin D helps the
body absorb more calcium. Many foods are fortified with this vitamin. It’s also
found in fatty fishes, such as salmon, mushrooms, and cheese.
Food and drinks to avoid on a kidney stone diet

Limit salt

High sodium levels in the body, can promote calcium buildup in urine. Avoid
adding salt to food, and check the labels on processed foods to see how
much sodium they contain. Fast food can be high in sodium, but so can
regular restaurant food. When you’re able, ask that no salt be added to
whatever you order on a menu. Also, take note of what you drink. Some
vegetable juices are high in sodium.

Lower your animal protein intake

Many sources of protein, such as red meat, pork, chicken, poultry, and eggs,
increase the amount of uric acid you produce. Eating large amounts of protein
also reduces a chemical in urine called citrate. Citrate’s job is to prevent the
formation of kidney stones. Alternatives to animal protein include quinoa, tofu
(bean curd), hummus, chia seeds, and Greek yogurt. Since protein is important
for overall health, discuss how much you should eat daily with your doctor.

Be mindful of oxalates

Eat oxalates wisely. Foods high in this chemical may increase formation of
kidney stones. If you’ve already had kidney stones, you may wish to reduce or
eliminate oxalates from your diet completely. If you’re trying to avoid kidney
stones, check with your doctor to determine if limiting these foods is enough.
If you do eat foods containing oxalates, always make sure to eat or drink a
calcium source with them. This will help the oxalate bind to the calcium during
digestion, before it can reach your kidneys. Foods high in oxalate include:

 chocolate

 beets

 nuts
  tea

 rhubarb

 spinach

 swiss chard

 sweet potatoes

Don’t drink colas

Avoid cola drinks. Cola is high in phosphate, another chemical which can
promote the formation of kidney stones.

Reduce or eliminate added sugar intake

Added sugars are sugars and syrups that are added to processed foods and
drinks. Added sucrose and added fructose may increase your risk of kidney
stones. Keep an eye on the amount of sugar you eat, in processed foods, such
as cake, in fruit, in soft drinks, and in juices. Other common added sugar
names include corn syrup, crystallized fructose, honey, agave nectar, brown
rice syrup, and cane suga