In
chronic orthostatic intolerance, patients are ill on a day-to-day basis. Chronic orthostatic intolerance may be confused with syncope because chronic illness is sometimes punctuated by acute syncopal episodes. However, this is unusual during real life (albeit common during artificial testing environments), and the author's work suggests no increase in the incidence of syncope above that in the general population. The physician should rely on the patient's history to determine whether chronic illness is present. Thus, chronic orthostatic intolerance is defined by a history of symptoms of orthostatic intolerance present on a day-to-day basis. Defining symptoms of chronic orthostatic intolerance include
dizziness in all patients, with high incidence of the following conditions:
- Altered vision (blurred, "white outs", "black outs")
- Fatigue
- Exercise intolerance (frequently post-exercise malaise)
- Nausea
- Neurocognitive deficits
- Sleep problems
- Heat [ Note: I think this is meant to be "Heat intolerance" ]
- Palpitations
A large proportion of patients also experience the following symptoms:
- Headache
- Tremulousness
- Difficulty breathing or swallowing
- Sweating
- Pallor
- Other vasomotor symptoms
These symptoms are divisible into symptoms of sympathetic activation and symptoms of reduced cerebral blood flow.