Aerobic exercise performed for 20 minutes a day, three times a week, is sometimes recommended for patients who can tolerate it. Exercise may have the immediate effect of worsening tachycardia, especially after a meal or on a hot day. In these cases, it may be easier to exercise in a semi-reclined position, such as riding a recumbent bicycle, rowing, or swimming.When changing to an upright posture, finishing a meal, or concluding exercise, a sustained hand grip can briefly raise the blood pressure, possibly reducing symptoms. Compression garments can also be of benefit by constricting blood pressures with external body pressure. Medication
If nonpharmacological methods are ineffective, medication may be necessary. Medications used may include beta blockers, pyridostigmine, midodrine, or fludrocortisone. As of 2013, no medication has been approved by the U.S. Food and Drug Administration to treat POTS, but a variety are used off-label. Their efficacy has not yet been examined in long-term randomized controlled trials.Fludrocortisone may be used to enhance sodium retention and blood volume, which may be beneficial not only by augmenting sympathetically mediated vasoconstriction, but also because a large subset of POTS patients appear to have low absolute blood volume.While people with POTS typically have normal or even elevated arterial blood pressure, the neuropathic form of POTS is presumed to constitute a selective sympathetic venous denervation. In these patients the selective Alpha-1 adrenergic receptor agonist midodrine may increase venous return, enhance stroke volume, and improve symptoms.
Another subtype, neuropathic POTS, is associated with denervation of sympathetic nerves in the lower limbs. In this subtype, it is thought that impaired constriction of the blood vessels causes blood to pool in the veins of the lower limbs. Heart rate increases to compensate for this blood pooling.In up to 50% of cases, there was an onset of symptoms following a viral illness. It may also be linked to vaccination, physical trauma, concussion, pregnancy, or surgery. It is believed that these events could act as a trigger for an autoimmune response that result in POTS.POTS is more common in females than males. It has also been shown to be linked in patients with acute stressors such as pregnancy, recent surgery, or recent trauma. POTS also has been linked to patients with a history of autoimmune diseases, irritable bowel syndrome, anemia, hyperthyroidism, fibromyalgia, diabetes, amyloidosis, sarcoidosis, systemic lupus erythematosus, and cancer. Genetics likely plays a role, with one study finding that one in eight POTS patients reported a history of orthostatic intolerance in their family. Autoimmunity
There is an increasing number of studies indicating that POTS is an autoimmune disease. A high number of patients has elevated levels of autoantibodies against the adrenergic alpha 1 receptor and against the muscarinic acetylcholine M4 receptor.Elevations of autoantibodies targeting adrenergic α1 receptor has been associated with symptoms severity in patients with POTS.More recently, autoantibodies against other targets have been identified in small cohorts of POTS patients.