While thumb sucking isn't an issue in babies or young children, adult thumb sucking may be embarrassing and in some cases may pose oral health problems .
Adult thumb sucking is more common that people think, but it is a secret habit. Most adult thumb-suckers are afraid they might get judged or.
Clinical psychologist Helen Nightingale says adult thumb-sucking happens automatically and can have a familial cause. 'It's often passed down.