Bladder stones are hard mineral masses that form in the bladder when minerals in concentrated urine crystallize, often due to an inability to completely empty the bladder. Symptoms include lower abdominal pain, burning during urination, frequent urination, and blood in the urine. Bladder stones are caused by issues like an enlarged prostate, nerve damage, kidney stones, dehydration, infection, or abnormalities in the urinary tract. They are diagnosed through urinalysis, CT scans, or ultrasounds and treated by breaking up the stones with lasers or surgically removing large stones.