Some researchers such as Dr. Elisabeth Kübler-Ross and others have posited sequential stages including denial, anger, bargaining, depression and acceptance. As research progressed over the past 40 years, many who worked with the bereaved found stage models too simplistic and instead began to look at processes, dynamics, and experiences common to all. John Bowlby, a noted psychologist, outlined the ebb and flow of processes such as Shock and Numbness, Yearning and Searching, Disorganization and Despair, and Reorganization. Bowlby and Parkes both note psychophysiologic components of grief as well. Included in these processes are:

Shock and numbness
Feelings of unreality, depersonalization, withdrawal, and an anesthetizing of affect. These feelings often occur early in grief, and may be a self-protective way of getting through the facts of the death. Persons often remark on how someone appears stoic or strong when they are actually in shock.
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Yearning and searching
The grieving person tries to locate the lost person. Normally this is a functional endeavor, as the 'lost' person is found, but in bereavement the searching is fruitless. This process has also been referred to as 'pining.' Common reactions include feelings and even cognitions of 'seeing' the deceased for fleeting moments, hearing the door at the time they used to come home, or even incorrectly 'finding' the person, for example in a crowd, although intellectually realizing this is not so. Actually feeling that one 'sees' or 'hears' the deceased ranges in report from 90% in Asian cultures to 10-15% in western cultures, although this may be more a factor of reporting bias than of actual experience. This process appears to be an attempt of the person to cognitively and emotionally begin to let go, by coming to terms with the reality of the loss.

Disorganization and despair
These are the processes we normally associate with bereavement, the mourning and severe pain of being away from the loved person. There are no easy answers to assuage this difficult experience: it must simply be endured, although it may take years of all of the above experiences overlapping, waxing and waning before the last process takes place.

Reorganization
Reorganization is the assimilation of the loss and redefining of life and meaning without the deceased. Many times, in widowhood, one is so much a part of their spouse, that new definitions of identity must take place for healing. For the elderly after a lifetime of defining themselves in terms of their marriage relationships, this may take the rest of their lives

Source: Internet Research