Kidney stones, also known as renal calculi, are formed from small crystals that grow over weeks or months to form stones. It is when these stones decide to move out of the kidneys and down to the bladder (via the ureters) and then urinated out (via the urethra), that you know you have a problem. A very painful problem.
The initial crystals are formed when calcium combines with other substances to form stones (calcium oxalate comprises 60 per cent of all kidney stones). Very small grain-sized stones can pass through the bladder and out with the urine. It is the larger stones (up to the size of a golf ball), that cause the problems. Apart from the side-splitting pain, complications from kidney stones include irreparable damage to delicate kidney tissue, increased risk of infection, blockage of the ureter and loss of function of the affected kidney.
If you have had a bout of kidney stones, there is a 75 per cent chance that you will form more. In short, it is best to prevent the formation of kidney stones if possible.
- Pain that comes as suddenly as it goes. Pain may be felt in the abdomen, back and groin area.
- Blood in the urine.
- Chills and fever.
- Nausea and vomiting.
What causes it?
- Men are more likely to form kidney stones than women.
- Kidney stones are often hereditary.
- Not drinking enough fluids. Kidney stones are more likely to form if you drink less than a litre of fluid a day.
- Certain medications can increase your tendency to form stones including chemotherapy, diuretics, aspirin and acyclovir.
- Struvite stones are caused by recurrent urinary tract infections. This type of stone affects more women than men.
What to do?
It is important to know which stone variety you are dealing with (your doctor will be able to let you know). For instance, if your stones are made from calcium oxalate, you will need to avoid foods high in oxalates. If your stones are made from uric acid, you will need to decrease purines in your diet and follow the principles outlined for gout.
- The most important thing you need to do to prevent a recurrence of kidney stones is to increase your fluids. Water is best, closely followed by kidney-friendly herbal teas (see Remedies, below). Drink 2–3 litres of fluid a day.
- For calcium-oxalate stones, avoid high-oxalate foods such as coffee (including decaf), tea, chocolate, cola, nuts, spinach, strawberries, rhubarb and beetroot.
- For uric-acid stones, avoid high-purine foods including offal or organ meats (liver, heart, spleen, intestines) and sweetbreads (thymus, pancreas), red meat, poultry, deli meats, shellfish, crustaceans, yeast, herring, sardines, mackerel, anchovies, asparagus, mushrooms and spinach.
- Although excess calcium may increase your risk of calcium-oxalate stones, this is not a reason to reduce dairy or calcium-rich foods from your diet as calcium plays an important role in the body. Instead, eat in moderation.
- Decrease salt (sodium chloride) in your diet. This means not adding salt to your cooking and meals, as well as getting serious about reducing packaged, processed and takeaway foods that hide horrific amounts of salt. Sodium increases the levels of calcium in urine, and increases the crystallisation of this mineral. Decreasing salt is also a good strategy for decreasing blood pressure, an extra burden on the kidneys. Happy kidneys are healthy kidneys.
- Normalise blood-sugar levels. High-circulating glucose (blood sugar) places a strain on the kidneys and is an early sign of diabetes. Avoid sugar, eat frequent meals to keep blood sugar steady and follow the recommendations for XX on page 00.
- Magnesium can help prevent kidney stones and facilitate an easier passing of them. Foods with a good magnesium to calcium ratio include barley, corn, buckwheat, rye, oats, brown rice, avocado, bananas, lima beans and potato.
- Reduce protein in your diet. The breakdown products of protein create more work for the kidneys. Red meat in particular increases the urinary excretion of calcium, phosphate, oxalate and uric acid – the entire mineral repertoire of the kidney stone. Reduce animal protein and incorporate more vegetarian protein sources including legumes, nuts and seeds.
- Kidney-friendly foods include watermelon, citrus fruits, pumpkin seeds and cranberries.
- Citrate is a molecule that binds to calcium in the urine, preventing the formation of stones. Citrate is found in citrus fruits (lemons, oranges, mandarins, tangerines and grapefruit).
- Drink the juice of half a lemon in hot water first thing in the morning. Good for your kidneys, liver and bowel.
- Herbs that act as a kidney tonic include crataeva (a key herb), shatavari, uva ursi, dandelion leaf, couch grass, marshmallow and corn silk. Take them in tablet or tincture form, or better still as a herbal tea. Double the action of great herbs for the kidneys and increase your fluid intake at the same time. You’re in luck as kidney herbs taste pretty good. Well, compared to sleep herbs or liver herbs.
- B6 can help reduce the production of calcium oxalate and prevent the formation of stones of this nature.
- Magnesium relaxes smooth muscle, allowing small stones to pass through more easily. It can also increase the solubility of calcium, reducing stone formation.
- Don’t take calcium supplements if you are prone to kidney stones, as most stones contain calcium. If, however, you have been advised to take extra calcium, choose a calcium citrate supplement that has less chance of stone formation.
- There has been torrid controversy in nutritional circles over whether vitamin C supplements can increase calcium oxalate stone formation. The final word is that taking vitamin C is absolutely fine, and will not increase your risk of stone formation. It is actually good for dissolving calcium phosphate stones and the less common magnesium ammonium phosphate stones (struvite).
- Weight-bearing exercise such as walking, jogging and gym work can help keep more calcium in the bones rather then being excreted in the urine.
- Kidneys are the organs of fear. Have you anything to fear or do you live your life fearfully? If you identify with feeling fearful, there are two Bach flowers that may assist. Mimulus is the one for known fears (eg fear of flying, fear of spiders) whereas Aspen is for generalised apprehension and anxiety.
At a glance
- Water is your friend. Keeping the kidneys flushed with fluid can help prevent crystals forming into stones. Drink at least 2 litres a day.
- Reduce salt (sodium) in your diet. Sodium increases the chance of calcium crystallising to form stones. Sodium also has the potential to increase blood pressure, which adds stress to the kidneys.Avoid adding salt to your meal and also be careful of processed, packaged and takeaway foods.
- Citrus fruits contain citrate that can help prevent the formation of stones.
- Eat more vegetarian protein foods such as legumes, nuts and seeds. A diet high in animal protein increases your risk of kidney stones.
- If your stones are calcium oxalate, reduce high oxalate foods such as coffee (including decaf), tea, chocolate, cola, nuts, spinach, strawberries, rhubarb and beetroot.
- Crataeva is the pick of the herbs that act as a kidney tonic, but take one or all of the herbs mentioned above as a tea or in tablets or tincture.
- B6 and magnesium can help reduce stone formation.
- Kidneys are the organs related to fear – is there anything in your life that is frightening you?