The bladder, an organ located near the bottom of the abdomen, is responsible for urination in both children and adults. When your bladder works properly, two sets of muscles allow you to control the retention and release of urine. Children who urinate excessively often have a health-related problem that prevents them from controlling their bladder and its functions.
Excessive urination means either urinating an abnormally frequent number of times or passing an abnormally large volume of urine during urination. The average adult urinates approximately five times each day, producing about 3 cups to 2 quarts of urine overall, according to the Merck Manuals. Children and infants generally urinate less; therefore, it's not uncommon for babies to produce only 1 cup of urine everyday.
Drinking more fluids can increase the volume and/or frequency of urination, and drinking less fluids can decrease the volume and/or frequency of urination. Both are normal occurrences. Your child has excessively frequent urination when he begins to urinate more often yet passes the same amount of urine that he usually does. Common causes of overly frequent urination in children include blockages in the urinary tract, pollakiuria, voiding dysfunction and a urinary tract infection, or UTI.
Urinary tract blockages, such as kidney stones or tumors, reduce the volume of urine that the bladder can hold, which makes more frequent urination necessary. Most common in children 3 to 8 years old, pollakiuria causes children to urinate up to 30 times daily, although each bathroom trip typically produces only a tiny amount of urine. Children with voiding dysfunction become unable to pass all of the urine in their bladder after they develop a habit of holding their urine for a long time instead of urinating when they need to. Reasons children avoid going to the bathroom include wanting to continue something they enjoy doing, such as playing, or not wanting to use a public bathroom. Unfortunately, voiding dysfunction contributes to UTIs, along with other bad bathroom habits, such as wiping incorrectly.
Common causes of an excessive volume of urine in children include diabetes insipidus, diabetes mellitus, inadequate nighttime levels of antidiuretic hormone and substances that act as a diuretic. Although diabetes mellitus is a fairly widespread condition characterized by too much blood sugar, diabetes insipidus is a rare medical problem related to insufficient production or improper processing of the antidiuretic hormone called vasopressin. Children can also urinate excessively at night if their body produces too litle antidiuretic hormone, or ADH, which normally reduces the volume of urine produced during sleeping. Using diuretics, such as caffeine or diuretic drugs, cause the body to produce large volumes of urine, as well.
If your child begins to urinate excessively, you should take her to a qualified health care professional capable of diagnosing the cause of the problem. Some conditions, including diabetes and UTIs, may require treatment in the form of medications, such as insulin or antibiotics. Other conditions, such as voiding dysfunction, often go away after you teach your child to modify her behavior. A third class of conditions typically disappear without intervention, such as pollakiuria, which frequently clears up with no treatment in about 12 weeks.