Diagnostic criteria for postural orthostatic tachycardia syndrome
| All of the following criteria are necessary: |
| A sustained increase in heart rate by ≥ 30 beats per minute within 10 minutes of standing or head-up tilt in adults (or ≥ 40 beats per minute for patients ages 12–19) without orthostatic hypotension (a fall in systolic blood pressure ≥ 20 mm Hg or diastolic blood pressure ≥ 10 mm Hg) |
| Associated symptoms of orthostatic intolerance that are worse with standing (light-headedness, fatigue, palpitations, tremulousness, blurred vision, syncope) and improve with recumbency |
| Symptom duration of at least 3 months |
| Absence of other conditions to explain sinus tachycardia (prolonged bed rest, medications, hyperthyroidism, anorexia nervosa, anemia, pain, fever, infection, dehydration) |
Based on information in reference 1, 2, 4, and 5