What can cause falls when theres no snow outside and youre walking and all of a sudden you fall and didnt see anything to trip over? is it medical?

Falls: Although unexplained falling may have a neurologic or orthopedic basis, if you have no other obvious symptoms or problems like lightheaded episodes, vertigo attacks or knee joint instability, in my opinion it's unlikely that a neurological or general physical examination will shed any light on your falling. However if you note lingering unsteadiness or confused feeling after falling get examined.