From the Guidelines
Feeling dizzy or experiencing a head rush when standing or sitting up quickly is typically due to a condition called orthostatic hypotension, which occurs when your blood pressure drops suddenly, as stated in the 2018 European Heart Journal guidelines 1. This happens because gravity pulls blood downward when you change positions, and sometimes your body doesn't compensate quickly enough by constricting blood vessels and increasing heart rate. To manage this, stand up slowly in stages - sit for a moment before standing completely, as recommended by the 2018 European Heart Journal guidelines 1. Stay hydrated by drinking 8-10 glasses of water daily, as dehydration can worsen symptoms. Avoid alcohol and limit caffeine, which can contribute to dehydration. If you take medications for high blood pressure, heart conditions, or certain psychiatric conditions, these may be contributing factors. For persistent or severe symptoms, consult your doctor, as they might adjust your medication dosage or timing. In rare cases, orthostatic hypotension can indicate underlying health issues like anemia, heart problems, or nervous system disorders. The basic mechanism involves your autonomic nervous system, which normally ensures adequate blood flow to your brain during position changes, but when this regulation fails temporarily, reduced brain blood flow causes the dizzy sensation. Some key points to consider include:
- Orthostatic intolerance, which can cause symptoms such as lightheadedness, palpitations, and fatigue upon standing, as described in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.
- Postural orthostatic tachycardia syndrome (POTS), a condition characterized by a rapid increase in heart rate and other symptoms upon standing, as defined in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.
- The importance of establishing the underlying diagnosis and treating the underlying cause of orthostatic hypotension, as emphasized in the 2001 European Heart Journal guidelines on management of syncope 1.
From the FDA Drug Label
Administration of midodrine results in a rise in standing, sitting, and supine systolic and diastolic blood pressure in patients with orthostatic hypotension of various etiologies Patients with orthostatic hypotension of any etiology and supine-to-standing fall of systolic blood pressure of at least 15 mmHg accompanied by at least moderate dizziness/lightheadedness
The cause of orthostatic dizziness and a rush to the head when standing up or sitting up is orthostatic hypotension, which is characterized by a significant drop in blood pressure when changing positions from lying down to sitting or standing. This condition can lead to a decrease in blood flow to the brain, resulting in symptoms such as dizziness, lightheadedness, and a rush to the head 2 2.
From the Research
Causes of Orthostatic Dizziness
- Orthostatic hypotension is a primary cause of dizziness upon standing, characterized by a decrease in blood pressure of 20 mm Hg or more systolic or 10 mm Hg or more diastolic within three minutes of standing 3
- Neurogenic orthostatic hypotension is a severely disabling condition due to deficient peripheral vasoconstrictor tone in response to the upright position, leading to symptoms of lightheadedness, dizziness, and visual "white-out" 4
- Autonomic dysfunction, including alpha-synucleopathies such as Parkinson's disease, Pure Autonomic Failure, and Multiple System Atrophy, can cause orthostatic hypotension and dizziness upon standing 5
- Non-neurogenic causes of orthostatic hypotension, such as medications like antihypertensives and tricyclic antidepressants, can also lead to dizziness upon standing 6
Symptoms and Diagnosis
- Symptoms of orthostatic hypotension include lightheadedness, weakness, blurred vision, fatigue, and lethargy, as well as falls 6
- Diagnosis is based on a thorough clinical examination, including measurement of blood pressure and heart rate in the supine and standing position 5
- The bedside simplified Schellong test, which consists of blood pressure and heart rate measurements after five minutes in the supine position and three minutes after moving to a standing position, can be used to confirm diagnosis 3
Risk Factors and Associations
- Orthostatic hypotension is associated with a significant increase in cardiovascular risk and falls, and up to a 50% increase in relative risk of all-cause mortality 3
- Risk factors such as diabetes mellitus increase the prevalence of orthostatic hypotension in all age groups 3
- Orthostatic hypotension is common in the elderly, with a prevalence of 20% in older adults and 5% in middle-aged adults 3