<unk>  is divided, roughly based on patient history, in two variants - acute and chronic. Acute<unk>  Patients who suffer from acute<unk>  usually manifest the disorder by a temporary loss of consciousness and posture, with rapid recovery (simple faints, or syncope), as well as remaining conscious during their loss of posture. This is different from a syncope caused by cardiac problems because the triggers for the fainting spell (standing, heat, emotion) and identifiable prodromal symptoms (nausea, blurred vision, headache) are known. As Dr. Julian M. Stewart, an expert in<unk>  from New York Medical College states, "Many syncopal patients have no intercurrent illness; between faints, they are well." Symptoms: * Altered vision (blurred vision, "white outs"/gray outs, black outs, double vision) * Anxiety * Exercise intolerance * Fatigue * Headache * Heart palpitations, as the heart races to compensate for the falling blood pressure * Hyperpnea or sensation of difficulty breathing or swallowing (see also hyperventilation syndrome) * Lightheadedness * Sweating * Tremulousness * Weakness A classic manifestation of acute<unk>  is a soldier who faints after standing rigidly at attention for an extended period of time. Chronic<unk>  Patients with chronic<unk>  have symptoms on most or all days. Their symptoms may include most of the symptoms of acute<unk> , plus: * Nausea * Neurocognitive deficits, such as attention problems * Pallor * Sensitivity to heat * Sleep problems * Other vasomotor symptoms.
Orthostatic intolerance
Hyperesthesia
Sarcopenia
Adynamia
Premastication
Exercise intolerance
Perfume intolerance
Carotidynia