Dunno. Maybe you should get it checked out.
If you used to say...stutter, or have facial tics, years ago, and now you're doing it again, then you could call that particular symptom 'regressing'. Maybe you're under stress. And its an emotional thing.
But losing balance while walking? Sounds like a physical thing.
Like (I get the impression that you're too young for this, but) a mild stroke? Or something like that. Dont wanna scare you, but if it keeps on then get it checked out.