Nightly numbness in hands and feet and the resulting insomnia are all too familiar sources of distress for modern people. In modern medicine, these symptoms are understood not simply as a circulatory disorder, but as a complex issue involving both the nervous and vascular systems. Most commonly, one may suspect peripheral neuropathy, a condition where the peripheral nerves distributed at the ends of the hands and feet are damaged or functionally impaired, causing paresthesia. It occurs due to diverse causes such as diabetes, thyroid disease, vitamin deficiencies, and autoimmune disease. In particular, when blood circulation is not smooth, sufficient oxygen and nutrients are not supplied to neurons, which can accelerate nerve injury. It is just like how even the finest car struggles to perform properly when the highway is congested. Furthermore, the concept of cold in Donguibogam can be linked to microcirculatory disturbance in modern medicine. If blood flow in the capillaries—the smallest blood vessels in our body—is impaired, the necessary oxygen and nutrients cannot properly reach the tips of the hands and feet. Especially in cold environments or stressful situations, sympathetic nerves become heightened and constrict blood vessels, which further decreases blood flow volume and serves as a major culprit worsening cold hypersensitivity of hands and feet and numbness. Such microcirculatory disturbance is commonly observed particularly in patients with diabetes or hypertension, and it can lead to a vicious cycle that triggers nerve injury and insomnia. Even conditions like restless legs syndrome, where an uncomfortable sensation in the legs creates an urge to move them without a clear cause, can be a major source of insomnia. Lying down to sleep brings an itching or crawling sensation in the legs that disrupts sleep. These symptoms are known to be closely associated with nervous system issues, such as dopamine imbalance or iron deficiency. Beyond simply being unable to sleep, sleep deprivation increases the systemic inflammatory response, weakens immunity, and leads to chronic fatigue and cognitive decline, markedly reducing quality of life. In particular, when sleep is disrupted at night by numbness in hands and feet, sleep depth and quality decrease; this in turn can cause autonomic nervous system imbalance, forming a vicious cycle that further exacerbates blood circulation problems. The autonomic nervous system, which maintains homeostasis in our body, responds very sensitively to stress or sleep deprivation, and as a result, its ability to regulate vascular constriction and dilation drops, which may worsen symptoms like numbness in hands and feet. In the end, the obstruction of qi and blood in Donguibogam and peripheral neuropathy and microcirculatory disturbance in modern medicine share the same core principle: they are signals that arise when the body balance is broken. Numbness in hands and feet that disrupts night sleep is not a symptom to simply endure or overlook, but an important warning light sent by our body that calls for active efforts to address it. In the next section, I will share very simple yet effective methods that can relieve this distress.
