Although conventionally focused on the emotional response to loss, grief also has physical, cognitive, behavioral, social, cultural, spiritual and philosophical dimensions.

The grief associated with death is familiar to most people, but individuals grieve in connection with a variety of losses throughout their lives, such as unemployment, ill health or the end of a relationship.

[3] Between 1996 and 2006, there was extensive skepticism about a universal and predictable "emotional pathway" that leads from distress to "recovery" with an appreciation that grief is a more complex process of adapting to loss than stage and phase models have previously suggested.

The main objective of the two-track model of bereavement is for the individual to "manage and live in reality in which the deceased is absent," as well as return to normal biological functioning.

Rubin (2010) points out, "Track 1, the range of aspects of the individual's functioning across affective, interpersonal, somatic and classical psychiatric indicators is considered".

[14] Bonanno's work has also demonstrated that absence of grief or trauma symptoms is a healthy outcome, rather than something to be feared as has been the thought and practice until his research.

The five stages are: This model found limited empirical support in a study by Maciejewski et al.[21] That is that the sequence was correct although Acceptance was highest at all points throughout the person's experience.

[22] Activation of the anterior cingulate cortex and vagus nerve is similarly implicated in the experience of heartbreak whether due to social rejection or bereavement.

In those individuals who avoid such thoughts, there is a related opposite type of pattern in which there is a decrease in the activation of the dorsal amygdala and the dorsolateral prefrontal cortex.

In those people who had greater intensity of sadness, there was a low functional connection between the rostral anterior cingulate cortex and amygdala activity, suggesting a lack of regulation of the former part of the brain upon the latter.

More recently, Bo Winegard and colleagues argued that grief might be a socially selected signal of an individual's propensity for forming strong, committed relationships.

Colin Murray Parkes in the 1960s and 1970s in England noted increased doctor visits, with symptoms such as abdominal pain, breathing difficulties, and so forth in the first six months following a death.

Critics of including the diagnosis of complicated grief in the DSM-5 say that doing so will constitute characterizing a natural response as a pathology, and will result in wholesale medicating of people who are essentially normal.

[36] The signs and symptoms characteristic of complicated grief are listed as "extreme focus on the loss and reminders of the loved one, intense longing or pining for the deceased, problems accepting the death, numbness or detachment ... bitterness about your loss, inability to enjoy life, depression or deep sadness, trouble carrying out normal routines, withdrawing from social activities, feeling that life holds no meaning or purpose, irritability or agitation, lack of trust in others".

They are also considered to be complicated because, unlike normal grief, these symptoms will continue regardless of the amount of time that has passed and despite treatment given from tricyclic antidepressants.

The Mental Health Clinical Research team theorizes that the symptoms of complicated grief in bereaved elderly are an alternative of post-traumatic stress.

These symptoms were correlated with cancer, hypertension, anxiety, depression, suicidal ideation, increased smoking, and sleep impairments at around six months after spousal death.

[37] A treatment that has been found beneficial in dealing with the symptoms associated with complicated grief is the use of serotonin specific reuptake inhibitors such as Paroxetine.

[49] Intervention and comforting support can make all the difference to the survival of a parent in this type of grief but the risk factors are great and may include family breakup or suicide.

[50][51] Feelings of guilt, whether legitimate or not, are pervasive, and the dependent nature of the relationship disposes parents to a variety of problems as they seek to cope with this great loss.

Parents, family members and service providers have all confirmed the unique nature of suicide-related bereavement following the loss of a child.

Only in more recent decades has this tradition been reduced to a period of two years, while some religions such as Orthodox Christianity many widows will still continue to wear black for the remainder of their lives.

[68] Childhood loss can predispose a child not only to physical illness but to emotional problems and an increased risk for suicide, especially in the adolescent period.

It may be found among survivors of combat, natural disasters, epidemics, among the friends and family of those who have died by suicide, and in non-mortal situations such as among those whose colleagues are laid off.

A person who strongly identifies with their occupation may feel a sense of grief if they have to stop their job due to retirement, being laid off, injury, or loss of certification.

[97] Moreover, one of the main differences between those with an intellectual disability and those without is typically the ability to verbalize their feelings about the loss, which is why non-verbal cues and changes in behavior become so important, because these are usually signs of distress and expressions of grief among this population.

[97][100] As such, it is important when working with individuals with neurodevelopmental disorders to remember that they may express and understand their grief in non-neuronormative ways, such as in perseveration and repeating words related to death (a form of echophenomena known as echothanatologia).

When a baby chimpanzee or gorilla dies, the mother will carry the body around for several days before she may finally be able to move on without it; this behavior has been observed in other primates, as well.

"[106] Jane Goodall has described chimpanzees as exhibiting mournful behavior toward the loss of a group member with silence and by showing more attention to it.

However, some other waterbirds, such as mute swans are known to grieve for the loss of a partner or cygnet, and are known to engage in pining for days, weeks or even months at a time.