aetiology

Last edited 04/2021 and last reviewed 07/2023

The causes of postural hypotension may be considered in terms of:

  • venous pooling of blood:
    • severe varicose veins
    • prolonged standing
  • impaired vasomotor tone:
    • diabetic autonomic neuropathy
    • Shy-Drager syndrome
    • Parkinson's disease
  • reduced muscle tone:
    • prolonged bed rest
  • hypovolaemia:
    • dehydration
    • exsanguination e.g. gastrointestinal bleed
  • drugs:
    • hypotensive agents
    • tranquilisers
    • phenothiazines
    • levodopa
  • Addisonian disease:
    • Addison's disease
    • hypopituitarism
    • abrupt cessation of steroid therapy
  • idiopathic

Alternatively can be consider in terms of neurogenic and non-neurogenic causes:

Neurogenic causes

  • neurodegenerative disease - e.g. as Parkinson's disease, Parkinson-plus syndromes
  • peripheral neuropathy - e.g. diabetes, vitamin B12 deficiency, renal failure, amyloidosis, rheumatological, autoimmune, and paraneoplastic conditions

Non-neurogenic causes

  • volume depletion - Anaemia, dehydration, haemorrhage, hyperglycaemia
  • cardiovascular disease - Aortic stenosis, hypertension, heart failure, atherosclerosis or vascular stiffening, arrhythmias
  • other - Adrenal insufficiency, physical deconditioning, ageing

Either mechanism

  • medications - alpha blockers, antihypertensives, nitrates, diuretics, selective serotonin reuptake inhibitors, tricyclic antidepressants, antipsychotics, beta blockers
  • alcohol consumption
    • short term: diuretic effect, impairment of vasoconstriction
    • long term or chronic: neurotoxic effects

Idiopathic

Reference:

  1. Low VA, Tomalia TA. Orthostatic Hypotension: Mechanisms, Causes, Management.J Clin Neurol. 2015 Jul; 11(3): 220-226.
  2. Gilani A et al. Postural Hypotension. BMJ 2021;373:n922 http://dx.doi.org/10.1136/bmj.n922