Patient's question:
My son is three years old. Recently, he has been urinating frequently, and each time it's just a little bit. What could be the reason for this??Is this a serious problem???
Doctor's answer:
Hello:"Frequency of urination" is a subjective symptom, referring to an increase in the number of times one urinates.
The bladder wall is composed of the "detrusor muscle," which primarily serves the functions of "urine storage" and "urine excretion." When the detrusor muscle contracts, it indicates urination. However, for most of the time, the bladder wall remains relaxed, meaning it is storing urine.
The average bladder capacity of a normal adult is about 400 milliliters. Typically, a slight urge to urinate occurs when the bladder stores 200 milliliters of urine, but people often easily ignore or forget this sensation until the bladder is close to being full, at which point the urge to urinate gradually becomes stronger. In other words, the minimum amount of urine excreted in each urination for a normal adult should be at least 200 milliliters, and urinating 300 milliliters is perfectly normal. If the environment does not allow for restroom use, it is possible to hold it until the bladder exceeds 400 milliliters, which is then considered true "holding urine." Children's bladders are smaller, but the principle is the same and is related to their age and height.
The Three Major Causes of Urinary Frequency
Whether someone is considered to have "urinary frequency" depends on "the number of urination times" and "the amount of urine excreted." The causes are typically divided into the following three major categories:
1. Urinary frequency caused by an increase in urine volume
In this case, the patient's bladder is normal, but urinary frequency occurs due to an increase in urine volume. For example: excessive fluid intake (i.e., drinking a lot leads to urinating a lot), or abnormal body fluid metabolism (e.g., diabetes, heart failure, ascites due to liver cirrhosis, edema due to kidney failure, diabetes insipidus, or taking diuretics). Since the patient's urine volume is large each time (hundreds of milliliters), the focus should be on reducing fluid intake and treating