Kidney stones are more likely to happen if you don’t drink enough fluids, if you’re taking some types of medication, or if you have a medical condition that raises the levels of certain substances in your urine. Water intake, diet, and medications are the three main methods of preventing kidney stones which are described further below:
To avoid getting kidney stones, make sure that you drink plenty of water each day to avoid becoming dehydrated. It is very important to keep your urine diluted to avoid waste products forming into kidney stones. You can tell how diluted your urine is by looking at its colour. The darker your urine is, the more concentrated it is. Your urine is usually a dark yellow colour in the morning because it contains a build-up of waste products that your body has produced overnight.
Normally, you should drink at least six to eight glasses (about 1.2 litres) of water each day. However, people who have had a kidney stone before are encouraged to increase their fluid intake to two to three litres each day in order to ‘flush out’ waste products that can cause stones to develop.
Drinks such as tea, coffee, and fruit juice can count towards your fluid intake, but water is the healthiest option and is best for preventing kidney stones developing. You should also make sure that you drink more than the recommended daily amount when it is hot, or when you are exercising, in order to replenish fluids that are lost through sweating.
If your kidney stone is caused by an excess of calcium, you may be advised to reduce the amount of oxalates in your diet. Oxalates prevent calcium from being absorbed by your body and can accumulate in your kidney to form a stone.
Foods that contain oxalates include:
- almonds, peanuts, and cashew nuts
- soy products
- grains, such as oatmeal, wheat germ and wholewheat
You should not reduce the amount of calcium in your diet unless your GP recommends it. Calcium is very important for maintaining healthy bones and teeth.
To avoid developing a uric acid stone, you should reduce the amount of meat, poultry, and fish in your diet.
The type of medication that your GP prescribes will depend on the type of kidney stone that you have. For example, if you have previously had a struvite stone, you may need to take antibiotics. Antibiotics will help to prevent bacteria from causing a urinary tract infection (UTI), which will infect your kidney and may create a stone. To avoid uric acid stone formation, you may be prescribed medication to change the levels of acid, or alkaline, in your urine e.g. Allopurinol.