The smallest part of our blood supply system is the capillaries which are tiny vessels that act as temperature regulators (among many other functions) and either conserve or release heat. Capillaries run throughout or bodies and are highly concentrated in our hands and feet. When damaged, capillaries are a serious issue for diabetics and now it has been discovered when the AV shunt is defective in function and interferes with capillary function, muscle and skin tissue cannot get proper nutrition or waste drawn away. Additionally, temperature regulation becomes an issue affecting nerve fibers.
The result is a build-up of lactic acid in muscle and deeper tissue affecting the muscular system and causes pain that can seem to ‘travel’ from areas of the body one day to the next and cause fatigue.
The sympathetic nervous system which uses the spinal cord for communication and the sensory fibers or nerve fibers that carry signals to the central nervous system, can have their communication disrupted by the results of AV shunt disorder and hypersensitized nerves send pain signals that can ‘travel’ as well. This explains why some selective serotonin reuptake inhibitors such as Cymbalta seem to help.