The causes of painless hematuria in young people: First, urinary tract tumors, which can lead to local mucosal rupture or necrosis in the center of the tumor, and hematuria, usually without pain, are often related to long-term exposure to paint products or benzene chemicals, long-term coffee consumption and a diet high in sugar can cause a higher incidence of bladder tumors. It is recommended to perform ultrasound examination of the urinary system to rule out the presence of related tumors or cystoscopy of the urethra to rule out the presence of tumors of the urinary tract. Second, stones in the urinary system, such as kidney stones or bladder stones, usually do not cause acute obstruction and therefore do not produce acute pain. However, stones in the ureter can cause obstruction and produce acute pain. When the stone rubs against the mucosa, a small amount of bleeding may occur, resulting in hematuria.