This video takes us on the fascinating journey through our excretory system to learn how our kidneys make pee.

Kidney Stones

As we learned in this module, the kidney plays a very important role in the body as it filters out waste products. Sometimes kidney stones can form when there is a build up of specific minerals in your urine. Kidney stones are hard, pebble-like pieces of material that form in one or both of your kidneys. They rarely cause permanent damage if treated by a health care professional.

Kidney stones vary in size and shape. They may be as small as a grain of sand or as large as a pea. Rarely, some kidney stones are as big as golf balls. Kidney stones may be smooth or jagged and are usually yellow or brown. A small kidney stone may pass through your urinary tract on its own, causing little or no pain. A larger kidney stone may get stuck along the way. A kidney stone that gets stuck can block your flow of urine, causing severe pain or bleeding.

There are different types of kidney stones, depending on what type of mineral buildup has occurred:

• Calcium stones. Calcium stones, including calcium oxalate stones and calcium phosphate stones, are the most common types of kidney stones. Calcium oxalate stones are more common than calcium phosphate stones. Calcium from food does not increase your chance of having calcium oxalate stones. Normally, extra calcium that isn’t used by your bones and muscles goes to your kidneys and is flushed out with urine. When this doesn’t happen, the calcium stays in the kidneys and joins with other waste products to form a kidney stone.
• Uric acid stones. A uric acid stone may form when your urine contains too much acid. Eating a lot of fish, shellfish, and meat—especially organ meat—may increase uric acid in urine.
• Struvite stones. Struvite stones may form after you have a UTI. They can develop suddenly and become large quickly.
• Cystine stones. Cystine stones result from a disorder called cystinuria that is passed down through families. Cystinuria causes the amino acid cystine to leak through your kidneys and into the urine.