Not to be confused with Pott disease . Condition in which a change from lying to standing causes an abnormally large increase in heart rate Postural orthostatic tachycardia syndrome Other names Postural tachycardia syndrome (POTS) Specialty Cardiology , Neurology Symptoms More often with standing: lightheadedness , trouble thinking , tachycardia , weakness,  palpitations , heat intolerance , acrocyanosis Usual onset Most common (modal) age of onset is 14 years  Duration > 6 months  Causes Antibodies against the Alpha 1 adrenergic receptor    Risk factors Family history  Diagnostic method An increase in heart rate by 30 beats/min with standing  Differential diagnosis Dehydration , heart problems, adrenal insufficiency , epilepsy , parkinson disease  Treatment Avoiding factors that bring on symptoms, increasing dietary salt and water, compression stockings , exercise, medications  Medication Beta blockers , Ivabradine , midodrine , and fludrocortisone .  Prognosis ~90% improve with treatment,  25% of patients unable to work  Frequency ~ 500,000 (US)  Postural orthostatic tachycardia syndrome ( POTS ) is a condition in which a change from lying to standing causes an abnormally large (or higher than normal) increase in heart beat rate .  This occurs with symptoms that may include lightheadedness , trouble thinking, blurred vision , or weakness.  Other commonly associated conditions include Ehlers–Danlos syndrome , mast cell activation syndrome , irritable bowel syndrome , insomnia , chronic headaches , chronic fatigue syndrome , and fibromyalgia .  Contents 1 Causation 2 Signs and symptoms 2.1 Brain fog 3 Causes 3.1 Autoimmunity 3.2 Secondary 4 COVID-19 5 Diagnosis 5.1 Diagnostic criteria 5.2 Autoantibodies against G-protein coupled receptor 5.3 Orthostatic intolerance 5.4 Differential diagnoses 6 Treatment 6.1 Medication 7 Prognosis 8 Epidemiology 9 History 10 Notable cases 11 References 12 Further reading 13 External links Causation [ edit ] The causes of POTS are varied.  Often, it begins after a viral infection, surgery, or pregnancy.  Risk factors include a family history of the condition.  Diagnosis in adults is based on an increase in heart rate of more than 30 beats per minute within ten minutes of standing up that is accompanied by symptoms.  Low blood pressure with standing , however, does not occur.  Other conditions which can cause similar symptoms, such as dehydration , heart problems, adrenal insufficiency , epilepsy , and parkinson disease , must not be present.  Treatment may include avoiding factors that bring on symptoms, increasing dietary salt and water, small and frequent meals,  avoidance of immobilization,  compression stockings , exercise program, and medications.     Medications used may include beta blockers ,  pyridostigmine ,  midodrine  or fludrocortisone .  More than 50% of people whose condition was triggered by a viral infection get better within five years.  About 80% have symptomatic improvement with treatment, but 25 percent of patients are still unable to work.   Retrospective studies has shown that five years after diagnosis 19% had a full resolution of symptom.  It is estimated that 500,000 people are affected in the United States.  The average age of onset is 20 years old, and it occurs about five times more frequently in females.  Signs and symptoms [ edit ] In adults the primary symptom is an increase in heart rate of more than 30 beats per minute within ten minutes of standing up.   The resulting heart rate is typically more than 120 beats per minute.  For people aged between 12 and 19, the minimum increase for diagnosis is 40 beats per minute.  This symptom is known as orthostatic (upright) tachycardia (fast heart rate). It occurs without any coinciding drop in blood pressure, as that would indicate orthostatic hypotension .  Certain medications to treat POTS may cause orthostatic hypotension. It is accompanied by other features of orthostatic intolerance —symptoms that develop in an upright position and are relieved by reclining.  These orthostatic symptoms include palpitations , light-headedness , chest discomfort, shortness of breath ,  nausea, weakness or "heaviness" in the lower legs, blurred vision , and cognitive difficulties.  Symptoms may be exacerbated with prolonged sitting, prolonged standing, alcohol, heat, exercise, or eating a large meal. [ citation needed ] In up to one third of people with POTS,  fainting occurs in response to postural changes or exercise.  Migraine -like headaches are common, sometimes with symptoms worsening in an upright position ( orthostatic headache ).  40-50% of patients with POTS develop acrocyanosis of extremities, a reddish-purple color in the legs and/or hands when they stand (indicative of blood pooling).    48% of people with POTS report chronic fatigue and 32% report sleep disturbances .     Others exhibit only the cardinal symptom of orthostatic tachycardia.  Additional symptoms are varied, and may include excessive sweating, a lack of sweating, heat intolerance, digestive issues such as bloating, nausea, indigestion, constipation, and diarrhea, a flu-like feeling, coat-hanger pain, forgetfulness, brain fog, and presyncope .  Brain fog [ edit ] One of the most disabling and prevalent symptoms in POTS is " brain fog ",  a term used by patient to describe the cognitive difficulties they experience. In one survey of 138 POTS patients, brain fog was defined as “forgetful” (91%), “difficulty thinking” (89%), and “difficulty focusing” (88%). Other common description was "Difficulty processing what others say" (80%), Confusion (71%), Lost (64 %), and "Thoughts moving too quickly" (40%)  The same survey described the most common triggers of brain fog to be fatigue (91%), lack of sleep (90%), prolonged standing (87%) and dehydration (86%). [ citation needed ] Neuropsychological testing has shown that a POTS-patient has reduced attention (Ruff 2&7 speed and WAIS-III digits forward), short-term memory ( WAIS-III digits back), cognitive processing speed ( Symbol digits modalities test ) and executive function ( Stroop word color and trails B ).    A potential cause for brain fog is a decrease in cerebral blood flow (CBF), especially in upright position.    Another theory is that interoception of excessive autonomic activity causes interoceptive prediction errors (PE) to occur.  A prediction error is the mismatch between a prior expectation and reality.  This would cause anxiety which then overwhelms the consciousness of pots-patient causing cognitive-affective symptoms.