The most common cause of hematuria in children is a urinary tract infection. The common symptoms are as follows:
- Fever
- Hesitant, difficult and painful urination
- Back pain, mostly found in older children
- Incomplete bladder emptying
- Frequent urination
In addition to urinary tract infection, other causes of hematuria include inflammation of the urinary tract, wounds in the genital organs or the urinary tract, injuries caused by an accident, excessive urinary calcium excretion, stones in urinary tract, or abnormalities in the blood vessels of the urinary tract or urinary bladder. However, the latter two conditions are seldom found in children. Furthermore, inflammation of the kidney is also frequently found and will be elaborated upon in a following section.
It is important to distinguish between blood urine and red urine to rightly determine the presence of either hematuria or another condition that is not caused by a problem with the urinary tract, including:
- Red urine, which is a change in the color of the urine without any kidney-related abnormalities, and is possibly caused by food items such as beetroot; food coloring; certain types of medicines, such as some anti-tuberculosis drugs, iron chelating agents, and certain types of antimalarial drugs; and chemotherapy. These can be taken alone or in combination with other medicines.
- Genetic diseases or inherited metabolic disorders, parts of which have been screened out since birth. Certain types of diseases of which the child has a family history and shown symptoms, and other physical examination can be used for diagnosis.
- Blood diseases usually found in children with this kind of underlying disease but previously unknown or never been detected before, including thalassemia G-6-PD, whose excessive breakdown of red blood cells when there is a stimulating stress such as from fever, infection or some types of foods and medicines. The latter two causes have an effect on the G-6-PD patient which can cause hemolysis of erythrocytes in the vessels, resulting in the change of urine into hematuria. Additionally, abnormalities such as blood coagulation or platelet disorders account for blood in the urine due to high tendency of bleeding. Although these abnormalities are not the direct result of problems with the kidney or urinary tract, they can do harm to the kidney, causing acute renal failure, which requires the patient to be hospitalized immediately.
Hematuria found in children due to problems in the urinary tract and the kidney can be roughly divided into two main groups.
- Emergency Group: patients are inflicted with acute nephritis. Symptoms include swelling in the eyes, legs, or body; high blood pressure; and impairment of the kidney function. Patients are required to be hospitalized immediately as there are possibilities of complications such as convulsions which are either as a result of the high blood pressure or metabolic disturbance, and possibility of acute renal failure which needs acute dialysis and supportive care to prevent life-threatening conditions and the chronic renal failure in the future.
- Non-Emergency Group: the color of the urine of patients in this category can be divided into the following groups.
- Bright red urine indicates that there are erythrocytes or blood spilling out to the urinary tract and its direct surroundings. The erythrocytes or blood come from urethral meatus, urethra, urinary bladder, ureter, uretic junction and the pelvis.

