The bodhran head suffers the most from varying climactic and environmental changes, as well as from the stresses put on it by a variety of playing styles and how much it is played. 

The following pertains primarily to a fixed (non tunable) drum head.

It is most important not to play a head that is too dry or tight. Upon picking up the drum, if it has a high-pitched ring, then the head wants to be carefully moistened with a little bit of water, though I prefer Guinness.  Many people will insist that's a waste of Guinness and the alcohol is bad for the head, I have drum heads that I've been playing on for decades that have had nothing but beer.

A drum head that is too loose is easily identified by its lack of response or sound, and is a trickier problem to solve. This drum head needs to be stored in a dry location for a period of time to allow it to dry out and tighten. How long this takes will depend on how loose the drum head has become. It's best to avoid using hair dryers or any prolonged exposure to heat. In extreme cases, one may need look into having the head replaced.