Answer by  
                                                                                          bethany91 (19)
                                                            
                          
                          
                                                           Hematuria, blood in the urine, is often caused by renal issues. Many times there is also protein or calcium found in the urine. When these crystalize, they can be very painful and become kidney stones. This can be because of kidney desease, genetic or otherwise, as well as environmental factors such as lack of water or excess  sodium in diet.