• Kidney stones Kidney stones are hard, pebble-like substances that form in the kidney when certain substances in the urine become highly concentrated. They can vary in size and shape, and they may be smooth or jagged. There are several types of kidney stones, including:
• Calcium stones: These are the most common type of kidney stones. They can be made of calcium oxalate or calcium phosphate.
• Uric acid stones: These stones form when the urine is too acidic. They are more common in people who eat a lot of protein or who have gout.
• Struvite stones: These stones form in response to an infection, such as a urinary tract infection.
• Cystine stones: These stones form in people with a rare genetic disorder that causes the kidneys to excrete too much of certain amino acids.

Symptoms of kidney stones can include:

• Pain in the side, back, or lower abdomen
• Pain or burning during urination
• Blood in the urine
• Nausea and vomiting
• Frequent urges to urinate
• Difficulty urinating or a weak urine stream