This build-up is either due to an overproduction or insufficient drainage of endolymph in the constant regulation of fluid in the inner ear.
[6] In contrast, a 2021 article by Richard Gacek posits that the hearing loss is actually caused by toxic nucleic acids that are released to the outer hair cells: "Since the outer hair cells (OHC) are freely surrounded by perilymph, their walls and nerve terminals are also bathed in this fluid.
The few type-II spiral ganglion cells in contact with the OHC are unlikely to play a significant role in hearing loss because of their low numbers and the lack of a known connection to the central auditory pathway.
Diagnosis is based on symptoms and a hearing test that documents a loss in the low and mid frequencies, usually only in one ear.
This occurs if the fluid increase leads to a leak or rupture of the membranes in the inner ear, causing a mixture of perilymph and endolymph.
The drug is thought to increase blood flow to the inner ear and to prevent the frequency and intensity of episodes.
[14] It is not FDA approved in the United States, yet has still been clinically observed to benefit patients, and is considered safer and more effective than diuretics.
Surgery is often reserved for cases where other measures have proven ineffective and/or when vestibular issues are the main complaint, as it runs the risk of causing hearing or other nerve damage.
However, because the organ of Corti undergoes stress during the hydrops episodes, long-term hearing loss, tinnitus, or hyperacusis is possible.
The data on how often progression to Meniere's disease occurs is mixed, but the majority of recent studies suggest a low likelihood.
However, the study was said to have limitations as "hearing fluctuations and the possibility of transitioning to Meniere's disease in the non-relapse group could not be completely ruled out.