Perilymph and endolymph have unique ionic compositions suited to their functions in regulating electrochemical impulses of hair cells.

The electric potential of endolymph is ~80-90 mV more positive than perilymph due to a higher concentration of K compared to Na.

[3] The main component of this unique extracellular fluid is potassium, which is secreted from the stria vascularis.

[citation needed] Disruption of the endolymph due to jerky movements (like spinning around or driving over bumps while riding in a car) can cause motion sickness.

[4] A condition where the volume of the endolymph is greatly enlarged is called endolymphatic hydrops and has been linked to Ménière's disease.