POTS (Postural orthostatic tachycardia syndrome) – more common in females. 

Orthostatic tachycardia (NOT hypotension, which suggests vasovagal syncope), dizziness, chest pain, palpitations, headaches, dyspnoea.  Sometimes bluish red discolouration in lower limbs. 

No known cause, can have sudden onset in previously fit individuals.  Associated with Ehlers Danlos (venous return problem?). 

Can be debilitating, associated with chronic pain, sleep problems, GI symptoms.  Can improve over time.  Diagnosis – heart rate increases by 30 beats per minute (bpm) or more (40bpm in those aged 12-19) within 10 minutes of standing, or if it increases to more than 120bpm. “Hyperadrenergic” POTS is where BP actually goes up, rather than down.

Monitor during valsalva manoeuvre to look for autonomic dysfunction.

Increase fluid intake to 2-3L daily. Increase salt intake?

Waist high compression stockings?

Consider treatment with beta blocker, fludrocortisone, desmopressin, clonidine, modafinil, SSRI.