What's the plural form of tarsalgia? Here's the word you're looking for.
Answer
The noun tarsalgia can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be tarsalgia.
However, in more specific contexts, the plural form can also be tarsalgias e.g. in reference to various types of tarsalgias
or a collection of tarsalgias.