Reddish urine often indicates hematuria, which generally suggests the presence of diseases in the urinary system. There are several kinds of diseases that cause hematuria. For the elderly, it is commonly caused by tumors in the urinary system, such as bladder tumors, kidney tumors, etc. The tumor tissue grows rapidly, or the blood vessels within the tumor tissue bleed. The rapid growth of tumor tissue, tumor tissue rupture or bleeding of blood vessels within the tumor tissue can easily cause hematuria, which is usually manifested as painless hematuria, and acute cystitis is also a very common cause of hematuria. Due to the presence of inflammation in the mucosa of the urinary tract, causing bleeding, will make the urine red, usually light red. In the case of urinary stones, bleeding can also be caused due to stone irritation of the urinary mucosa, which increases the red blood cells in the urine and produces hematuria. Other diseases, such as chronic nephritis and nephrotic syndrome, can also cause hematuria because the glomerular filtration membrane is damaged, which can cause red blood cells in the circulating blood to leak into the kidneys and increase the red blood cells in the urine. Tuberculosis of the urinary tract and prostatic hyperplasia are also very common causes of hematuria.