Just as Donguibogam emphasized the importance of suksu and the spleen and stomach, modern medicine finds the cause of muscle spasms in our body's fluid and electrolyte balance. Nocturnal leg cramps, where cramps strike the legs specifically at night, often occur through a complex interplay of dehydration, imbalances in specific minerals, and excessive excitability of the neuromuscular junction.
Our bodies are about 60% water, and important electrolytes such as sodium, potassium, calcium, and magnesium are dissolved in this water. These electrolytes play essential roles in transmitting nerve signals and regulating cell function during muscle contraction and relaxation. For example, calcium induces muscle contraction and magnesium aids muscle relaxation, working like partners. However, even a slight shift in the concentration of these electrolytes can disrupt the electrical stability of muscle cells, causing unintended contraction, or cramps.
At night in particular, fluid intake decreases during sleep, and as electrolytes are lost through sweat or urine, the concentration of fluids and electrolytes in the body can subtly change. You become even more vulnerable if fatigue has built up in the muscles from high activity during the day, or if you failed to sufficiently replenish fluids and electrolytes after exercising. Furthermore, electrolyte imbalances can easily occur when taking certain medications, such as diuretics or blood pressure medications, or when there are underlying diseases such as kidney disease, hypothyroidism, and diabetes.
The body's autonomic nervous system also plays an important role. When the balance between sympathetic nerves and parasympathetic nerves is disrupted, blood circulation is impaired, and the supply of oxygen and nutrients to muscles becomes inefficient, causing fatigue substances to accumulate and triggering muscle spasms. The function of the spleen and stomach in Donguibogam can be viewed as closely connected in modern medicine to electrolyte absorption and metabolism in the digestive system, as well as the regulation of the autonomic nervous system. In other words, if consumed water and nutrients do not properly reach the muscles through blood and body fluids, nerves become hypersensitive and muscles stiffen easily. Therefore, legs that cramp every night should be understood not simply as being tired, but as a warning signal sent by your body's fluid and electrolyte balance.
