Are mood swings after giving birth merely a passing case of the blues? Or are they a sign of something more serious, such as postpartum depression? For many women, the "baby blues" pass quickly. They appear just after childbirth, and are characterized by mood swings—from feeling very happy to feeling very sad. A woman may cry for no reason, or feel impatient, irritable, restless, anxious or lonely, says the National Women's Health Information Center.