The need for improved balance and control; feeling helpless.
Going beyond safe boundaries and losing yourself; overextension.
A phobia: The fear of falling (or fear of heights) may manifest in a dream to help you overcome the anxiety.
Letting go of something you perceived as an important foothold can cause falling dreams, like the first time a young person moves into her / his own apartment.
Lost status or the proverbial “fall from grace.”
(see Abyss, Cliff, Climbing, Ladder, Stairs)