Galen gives manifest causes for this disease, such as diarrhoea, haemorrhage, weakness, hectic fever, and long sickness, for then the weakness is great and consumes the spirits, as those recovering from a long sickness have but little blood and heat and spirit in them, and natural heat. Therefore the heart is weak, and when a burden is put on anything weak, it trembles suddenly, and is very unsteady (?)250 because of it.