see also:

• hypertension

• for most patients with hypertension, BP is chronically elevated but some people with or without pre-existing hypertension may develop a sudden transient surge in their BP, mostly this is driven by the sympathetic system in response to severe pain, distress or anxiety and will usually settle when these are addressed, but there are some more serious albeit less common causes to consider and in these situations, the surge may constitute a hypertensive crisis requiring emergent Rx if there is evidence of end organ damage

• increased sympathetic drive
  • severe pain, distress or anxiety
  • physical exertion, especially weight lifting types which cause sudden very brief surges in BP
  • sexual activity
  • hyperthyroidism may cause sudden surges
• adrenergic storm
  • cocaine
  • amphetamines and related psychostimulant substances
  • metamphetamine / meth / ice
  • phaeochromocytoma
  • excessive caffeine or tyramine
  • monoamine oxidase inhibitors (MAOIs) with tyramine
  • subarachnoid haemorrhage (SAH)
  • stroke (CVA)
  • etc
• acute activation of renin-angiotensin-aldosterone system (RAAS) causing vasocontriction and salt retention
  • acute renal ischaemia
    • renal artery stenosis (RAS)
      • while RAS typically causes sustained hypertension, it may precipitate acute, transient BP surges through RAAS dysregulation or medication interactions
      • patients with bilateral RAS or stenosis in a solitary kidney are prone to flash pulmonary oedema and hypertensive crises due to impaired pressure-natriuresis and global renal hypoperfusion, especially when volume-depleted or on RAAS-blocking medications
      • RAS combined with dehydration may cause renal ischaemia
      • ACE inhibitors and angiotensin II receptor blockers (ARBs) can cause paradoxical BP surges in patients with advanced RAS by triggering renal ischaemia
      • non-steroidal anti-inflammatory drugs (NSAIDs), especially with dehydration or ACE inhibitors or angiotensin II receptor blockers (ARBs)
    • renal artery vasospasm
      • blunt trauma
      • catheterisation of the artery
      • medications such as triptans
    • aortic dissection - esp. Type B extending down to the renal arteries
    • renal artery thrombosis
    • scleroderma
    • collagen vascular diseases
• other causes:
  • obstructive sleep apnoea (OSA)
  • eclampsia

NB. aldosterone-producing tumors (Conn's syndrome) generally cause sustained moderate to high hypertension rather than sudden surges; NB. cortisol-producing tumors (Cushing’s syndrome) generally cause sustained mild to moderate hypertension