Orthostatikus

Orthostatikus, or orthostatic, refers to bodily changes that occur when a person moves from lying or sitting to standing. The term is commonly used in physiology and medicine to describe how gravity affects blood pressure and heart rate, and how the body compensates to maintain cerebral perfusion.

A well-known example is orthostatic hypotension, defined as a sustained drop in blood pressure within about three minutes of standing—typically a fall of at least 20 mmHg systolic or 10 mmHg diastolic—often accompanied by dizziness, lightheadedness, blurred vision, or even syncope. The underlying mechanism involves venous pooling in the legs and abdomen after standing, reduced venous return to the heart, and inadequate autonomic compensatory responses.

Causes of orthostatic hypotension can be broadly categorized as non-neurogenic and neurogenic. Non-neurogenic causes include dehydration, acute blood loss, fever, medications (such as diuretics, vasodilators, alpha-blockers), and prolonged bed rest. Neurogenic orthostatic hypotension results from dysfunction of the autonomic nervous system, as seen in diabetes with autonomic neuropathy, Parkinsonian disorders, multiple system atrophy, or other neurodegenerative conditions.

Diagnosis combines clinical history with blood pressure measurements taken during posture changes. Tests may include an active standing test or tilt-table test to confirm the drop and to assess autonomic function.

Management focuses on addressing the underlying cause and reducing symptoms. Nonpharmacologic strategies include slow position changes, adequate hydration, increased salt intake when appropriate, and compression stockings. Physical counter-maneuvers and regular, moderately intense exercise can help. Pharmacologic options, used with caution, include vasoconstrictive agents such as midodrine or mineralocorticoids like fludrocortisone. Monitoring for comorbid conditions and avoiding medications that worsen hypotension are also important. Orthostatikus-related conditions commonly affect older adults and may increase the risk of falls.