No one knows exactly what causes kidney stones to form, but experts agree diet and dehydration play a large role. Stones typically form when minerals and other substances in urine crystallize inside the kidney. When people don't consume enough liquids, their urine is more likely to have higher concentrations of such substances.

Foods such as meat, salt, tea, spinach, chocolate and nuts also contain kidney stone-causing substances, which may spur the development of stones.

Symptoms of kidney stones include sharp pains in the back or side as the stones work their way to the bladder. Other symptoms include nausea, vomiting, bloody urine and a constant urge to urinate.

Most stones will pass through a person's body on their own within a few weeks because they are small - no larger than the tip of a pencil. Larger stones that don't pass naturally are broken up either with shock waves or lasers.

Medical experts say the best way to avoid getting kidney stones is to drink plenty of fluids, especially water, to prevent dehydration. Adding lemon to water may help because the acidic nature of lemon will dissolve crystal formations. People are also advised to eliminate salt from their diet because it may cause crystals to build up in the urine.