Is nerve fiber density referring to the number of axons within the fiber or the number of dendrites within it? what even is a fiber? confused! are nerve endings dendrites? how could fiber density be measured if a fiber is the same as one axon?

Nerve fiber density: Nerve fiber density is typically measured as a specific number of small nerve fibers in a sample of skin from a biopsy. This is useful when diagnosing Neuropathy's (problems with sensory conduction from specific areas of skin ie/ numbness or tingling) or regional pain syndromes.

Testing nerves: Skin punch biopsies used to evaluate sensory neuropathies include microscopic testing for "nerve fiber density", a measure of small unmyelinated axons mediating pain and temperature sensations. Recommend you expand your understanding by conferencing with the doctor who evaluated you and discern the significance of the density data.