What does the deficiency of qi and blood described in Donguibogam mean in modern medicine? The sensation of the world spinning whenever you stand up can be explained by orthostatic hypotension. This symptom is an important signal that our complex autonomic nervous system and circulatory system are not functioning properly, going far beyond merely having low blood pressure.
Orthostatic hypotension refers to a condition where, upon standing up suddenly from a sitting or lying position, systolic blood pressure drops by 20 mmHg or more, or diastolic blood pressure drops by 10 mmHg or more, causing dizziness, lightheadedness, or even syncope. Because the body is influenced by gravity, standing shifts approximately 500 to 700 mL of blood toward the legs and abdomen. In a healthy person, the body senses this change and immediately triggers compensatory actions.
The core of this compensatory mechanism is the autonomic nervous system. The autonomic nervous system oversees essential life-sustaining functions without conscious effort, such as heartbeat, blood pressure regulation, and digestion. Upon detecting a drop in blood pressure when standing, baroreceptors in the carotid arteries and aortic arch inform the brain. The brain then activates the sympathetic nervous system, a branch of the autonomic nervous system. The sympathetic nerve increases heart rate and constricts blood vessels throughout the body to elevate blood pressure again. In particular, it constricts veins in the legs and abdomen to enhance venous return, sending more blood back to the heart. This series of processes maintaining blood pressure within a normal range is called the baroreflex.
However, in patients with orthostatic hypotension, this baroreflex often fails to operate properly, much like a broken internal automatic regulator. There can be several causes, including inadequate sympathetic nervous system activation, improper blood vessel constriction, or an inability of the heart itself to pump sufficient blood.
Causes are diverse. First, dehydration is one of the most common causes. Insufficient fluid intake reduces blood volume, making it inherently difficult to maintain blood pressure. Next, taking certain medications, such as hypertension drugs, diuretics, antidepressants, or sedatives, can affect the autonomic nervous system and induce hypotension. Prolonged bed rest or nutritional deficits from extreme dieting can also impair blood volume and vascular regulatory capability.
Furthermore, chronic orthostatic hypotension can be a signal of other underlying diseases. For instance, neurodegenerative diseases like Parkinson's disease can impair autonomic nervous system function, complicating blood pressure regulation. Diabetic neuropathy can also damage nerves regulating blood pressure, leading to orthostatic hypotension. Although rare, endocrine diseases such as adrenal insufficiency or specific heart conditions like heart failure or bradycardia can be causes. Abnormalities in the renin-angiotensin-aldosterone system (RAAS), which regulates fluid and salt balance, or in antidiuretic hormone (ADH) secretion can also disrupt blood volume regulation and provoke hypotension.
Diagnosis is typically made through tests such as the tilt table test or 24-hour blood pressure monitoring, with treatments varying according to the underlying disease. In many cases, however, lifestyle improvements alone offer significant benefits. Just as Donguibogam emphasizes the balance of qi and blood, modern medicine likewise values a fundamental approach that helps the body’s autonomic nervous system and circulatory system function smoothly. Do not ignore the subtle signals sent by your body, and offer care and attention so your body’s powerhouse can operate healthily.
