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