Bed wetting usually is nothing to worry about until 16 to 17 years of age.
A lot of kids wet the bed due to weak bladder muscles from potty training age and up until 17 years old and some adults never grow out of the bed wetting problem.
If the person is still wetting the bed past 16 then a doctors visit would be a good idea but usually they'll outgrow bed wetting before 18.
I wet the bed when I was 5 and finally outgrew bed wetting by age 15.