Having deep sleep disrupted in the middle of the night because of the bathroom is a truly difficult experience. Modern medicine also views nocturia not as a single symptom, but as the result of various causes acting in combination. Unpacking the concepts of 'kidney qi deficiency' and 'deficiency cold of the lower jiao' found in Donguibogam into the language of modern science makes them much easier to understand clearly.
One of the biggest causes is an imbalance of 'antidiuretic hormone (ADH).' Normally at night, our body increases the secretion of antidiuretic hormone to suppress urine production and concentrate it, reducing the frequency of bathroom visits while sleeping. However, with aging or certain conditions, the secretion of this antidiuretic hormone decreases or fails to be properly secreted at night, leading to the symptom of 'nocturnal polyuria' where an excessive amount of urine is produced during the night. It is as if our body's 'urine lock' does not function properly at night.
Second is the 'change in bladder function.' With age, the elasticity of the bladder muscle decreases, and the bladder's storage capacity itself also declines. Moreover, the bladder can become sensitive and easily stimulated even by small amounts of urine, leading to accompanying symptoms of 'overactive bladder.' Interpreting the Donguibogam's statement that 'the bladder cannot contain urine' from a modern perspective means that the bladder's storage capacity and its ability to regulate contraction and relaxation have weakened.
Third, nocturnal hypoxia such as a 'sleep disorder' or 'sleep apnea' can also induce nocturia. When sleep quality drops, the secretion of antidiuretic hormone from the brain can be suppressed, and intermittent hypoxia due to sleep apnea increases cardiac strain, stimulating the secretion of a hormone called 'atrial natriuretic peptide (ANP).' This ANP exerts a diuresis action that increases urine production, potentially causing more urination at night. It becomes a vicious cycle where an inability to sleep causes another disruption to sleep.
Lastly, chronic diseases such as hypertension, diabetes, heart failure, and kidney disease, or certain medications like diuretics, are also significant causes of nocturia. In diabetes in particular, when blood glucose is not controlled, the kidneys try to discharge more fluid, increasing urine volume. In heart failure patients, fluid accumulated in the legs during the day is reabsorbed into the bloodstream when lying down at night and flows into the kidneys, which can cause a rapid surge in urine volume. For men, it is also common for the bladder neck to become obstructed by benign prostatic hyperplasia, worsening the sensation of residual urine and intensifying nocturia.
In this way, modern medicine analyzes nocturia from diverse perspectives, and many parts connect with the kidney-bladder philosophy of Donguibogam. Ultimately, both Eastern and Western medicine speak with one voice in that it is a signal appearing when our body's harmony and balance are broken. Therefore, if you are tossing and turning at night, it is truly important to find the precise cause and treat it together with your attending physician, rather than bearing it alone.
