A healthy adult is someone who is able to be assertive when necessary. A healthy adult is able to be emotionally available to others in significant, positive and caring ways. An adult who possesses positive self-esteem is someone whose life thrives.
If you find yourself unable to care for or about yourself, or you are experiencing difficulties in creating or maintaining meaningful and fulfilling relationships with others, there may be an issue of impaired self-esteem. This would appear as an inability to trust others, a fear of being vulnerable, rejected or abandoned. This would also result in a personal identity or sense of self that comes from someone or something outside of oneself, such as what you do, where you work, who you date, how you dress, etc. People with self-esteem or identity issues also have difficulties setting limits with others and are either aggressive and/or passive, either intimidating others or acting as a doormat.
If you are experiencing these kinds of challenges and know you need to change in order to have the life you really want, then therapy may be a viable option for you.