Causes of swelling

Of these causes, some arise from matter, and some from the constitution of the organ. As for the causes due to matter, this is the overflow of the six things mentioned above, and as for the causes due to the composition of the organs, these are the strength of the expelling organ, the weakness of the organ receiving excess and its predisposition to receive excess, either this occurs due to the nature of the substance and because the organ is created for this purpose, such as the skin, or due to the fact that it is lean, such as loose meat in three depressions - behind the ear at the neck, under the armpits and in the groins, and also the widening of the paths leading to the organ and the narrowness of the paths leading from it. Tumors are also formed due to the location of an organ under another organ, or because it is small and cramped for the nutrients entering it, or too weak due to damage to digest nutrients, or from a blow that locks the matter in it, or from stopping the dissolution of what is dissolved in it due to physical exercise, or from excessive heat attracting excess. This warmth is either natural, like meat, or acquired and born of pain or sudden movement, or some kind of warming substance.

Fractures cause swelling due to any of the reasons mentioned, such as crushing, compression of the organ and traction by which the bone is reduced. The bones themselves, even the teeth, sometimes swell, since they receive growth from food, and perceive moisture and putrefaction, which is why they are capable of swelling.