Table 1.

Co-morbidities in patients diagnosed with Postural Orthostatic Tachycardia Syndrome.

Comorbidity	Number (%) (of 3933 respondents)
Migraine headaches	1557 (40%)
Irritable bowel syndrome	1192 (30%)
Ehlers-Danlos syndrome	994 (25%)
Chronic Fatigue Syndrome	809 (21%)
Asthma	798 (20%)
Fibromyalgia	786 (20%)
Raynaud’s phenomena	610 (16%)
Iron deficiency anemia	628 (16%)
Gastroparesis	548 (14%)
Vasovagal syncope	499 (13%)
Inappropriate sinus tachycardia	448 (11%)
Mast cell activation disorder	353 (9%)
Autoimmune disease	616 (16%)
Hashimoto’s thyroiditis	228 (6%)
Celiac Disease	133 (3%)
Sjogren’s Syndrome	112 (3%)
Rheumatoid Arthritis	93 (2%)
Lupus	81 (2%)
Other	160 (4%)