Duration
Postpartum blues may last a few days up to two weeks. If symptoms last more than two weeks, the individual must be evaluated for postpartum depression. Causes
The causes of postpartum blues have not been clearly established. Most hypotheses regarding the etiology of postpartum blues and postpartum depression center on the intersection of the significant biological and psychosocial changes that occur with childbirth. Psychosocial causes
Pregnancy and postpartum are significant life events that increase a womans vulnerability for postpartum blues. Even with a planned pregnancy, it is normal to have feelings of doubt or regret, and it takes time to adjust to having a newborn. Feelings commonly reported by new parents and lifestyle changes that may contribute to developing early postpartum mood symptoms include:
Fatigue after labor and delivery
Caring for a newborn that requires 24/7 attention
Sleep deprivation
Lack of support from family and friends
Marital or relationship strain
Changes in home and work routines
Financial stress
Unrealistic expectations of self
Societal or cultural pressure to "bounce back" quickly after pregnancy and childbirth
Overwhelmed and questioning ability to care for baby
Anger, loss, or guilt, especially for parents of premature or sick infants

Risk factors
Most risk factors studied have not clearly and consistently demonstrated an association with postpartum blues. These include sociodemographic factors, such as age and marital status, obstetric factors, such as delivery complications or low birth weight.Factors most consistently shown to be predictive of postpartum blues are personal and family history of depression.
However, there exists some discussion in the literature of the possibility that postpartum blues may be an independent condition. Criteria
There are no standardized criteria for the diagnosis of postpartum blues. Unlike postpartum depression, postpartum blues is not a diagnosis included in the Diagnostic and Statistical Manual of Mental Disorders. Investigators have employed a variety of diagnostic tools in prospective and retrospective studies of postpartum blues, including repurposing screening tools, such as the Edinburgh Postnatal Depression Scale (EPDS) and Beck Depression Index (BDI), as well as developing blues-specific scales. Examples of blues-specific scales include the Maternity Blues Questionnaire and the Stein Scale. Differential diagnosis:-
Although symptoms of postpartum blues present in a majority of mothers and the condition is self-limited, it is important to keep related psychiatric conditions in mind as they all have overlap in presentation and similar period of onset. Postpartum anxiety
Symptoms of anxiety and irritability are often predominant in the presentation of postpartum blues. However, compared to postpartum anxiety, symptoms of postpartum blues are less severe, resolve on their own, and last fewer than two weeks. Postpartum depression
Postpartum depression and postpartum blues may be indistinguishable when symptoms first begin. However, symptoms of postpartum blues are less severe, resolve on their own, and last fewer than two weeks. Mothers who experience severe postpartum blues appear to be at increased risk of developing depression. Postpartum psychosis
Although both conditions can cause periods of high and low moods, the mood swings in postpartum psychosis are significantly more severe and may include mania, hallucinations, and delusions.