What are kidney stones?
A kidney stone, also known as a renal calculus, is a solid crystal build-up formed in the kidneys from dietary minerals in the urine. Stones can occur within the kidney itself as well as in the ureter (the tube draining urine from the kidney) or in the bladder.
What are the symptoms of kidney stones?If symptoms do occur, they include one or more of the following:
- Kidney pain-A stone that is stuck in a kidney may cause pain in the abdomen.
- Renal colic-This is a severe pain which comes and goes as a result of a stone passing through the ureter.
- Infection-Urine infections are more common in people with kidney stones. Symptoms of an infection include fever, pain when passing urine and increased frequency of passing urine.
- Bleeding- A stone can rub against the inside of the ureter, causing blood to pass in urine.
What causes kidney stones?
- Unknown cause- In most cases, the reason for a stone forming is not always known.
- Underlying causes- In a small number of cases, a medical condition is the cause. Some uncommon conditions can lead to higher than normal levels of chemicals in the body, such as calcium, oxalate, uric acid and cystine. If the level of these chemicals is high enough, they can form stones.
- Medicines- Certain medicines can increase chances of developing kidney stones. These include diuretics (water tablets), some chemotherapy drugs used in the treatment of cancer and some drugs used to treat HIV.
Do kidney stones form in one or both kidneys?
The majority of renal stones are found in one kidney. However, bilateral renal calculi can occur in 10 – 15% of patients.
Do all stones require surgery?
No. Some stones can pass spontaneously without medical or surgical intervention. The size and the location of the stone are factors that may effect whether a stone will pass spontaneously. Stones that are smaller than 4 mm have a 40-fold greater chance of passing spontaneously.
How much fluid should a person drink to prevent kidney stone formation?
People who have had a kidney stone should drink enough water and other fluids to produce at least 2 liters of urine a day. The amount of fluid each person needs to drink depends on the weather and the person’s activity level, people who work or exercise in hot weather need more fluid to replace the fluid they lose through sweat.
What can be done to help prevent a recurrence of a kidney stone?
If one stone is detected, there is less chances to have a recurrence by drinking plenty of water throughout the day. By keeping urine diluted there is reduced chance of chemical build up. For few people further specific advice may be given, for example:
- A dietitian may advise people with calcium oxalate stones to reduce the oxalate content of their diet. This may include limiting foods such as rhubarb, coffee and spinach.
- Uric acid stones can be prevented with medication.
- Other advice from a specialist may be appropriate for rarer conditions. Conatct Us