Grief is the process by which we adjust to the loss of a close relationship. Therefore, grief is an inevitable companion to love and attachment. The lives of those we love are interwoven with our own in thousands of small and large ways. One’s immediate family, in particular, contributes to a sense of comfort, security, and happiness and reinforces behavior. Endocrine function can become entrained by cues from another person. When this happens, losing that person requires a period of physiological adjustment. In all cases, loss of a loved one engenders feelings of loneliness, sadness, and vulnerability. The death of someone close also makes one’s own death imaginable, thus evoking fear of dying. When a person experiences the death of someone close, that person is confronted by mortality and undergoes a certain degree of acute separation distress. Sometimes, there is also guilt about being alive when the other person has died, or there is guilt about not being able to save the person or make his or her life or dying easier.