先天不足

congenital deficiency / inherent weakness

early / prior / former / in advance / first

embryonic period (contrasted with 後天|后天 [hou4 tian1]) / inborn / innate / natural

day / sky / heaven

no; not so / (bound form) not; un-

insufficient / lacking / deficiency / not enough / inadequate / not worth / cannot / should not

excessive

foot / to be sufficient / ample

to be born with a weak constitution and suffer from ill health during one's life / (fig.) to be problematic from the start, and get even worse over time