Though both terms are often used interchangeably, sadness is generally regarded -- from a clinical standpoint -- as the precursor of depression, which can make leading a normal life difficult. However, a growing body of research suggests that sadness -- if it's not addressed -- affects physical well-being, as well as emotional well-being. Failure to cope adequately with sadness imposes higher stress on the body, which can result in autoimmune diseases, heart problems, and a greater tendency toward self-harming behavior.
Losing a spouse can trigger significant cardiovascular stress. One indication is revealed in a study published in the Journal of the American Medical Association's spring 2014 issue. According to the study, surviving partners were twice as likely to suffer a heart attack or stroke within 30 days after the loss. The risk roughly doubled -- from eight of every 10,000 people whose spouses were still alive, to 16 of every 10,000 individuals whose spouse or partner had died. Stress-induced changes in blood pressure and heart rates are also likely. Although it's small, the link suggests the bereaved partner may pay less attention to his own health, leaving him vulnerable to cardiovascular issues.
Compromised Immune Systems
Evidence suggests that sadness can suppress the body's immune system, leaving it more vulnerable to autoimmune diseases like arthritis and multiple sclerosis, states the PsychCentral website. Negative emotions like anger, loneliness and trauma can release higher levels of stress hormones like adrenaline and cortisol. The release of these hormones results in heightened energy and awareness, which helps in dealing with traumatic situations, or sudden environmental changes. Failure to shut off these hormones, however, can compromise the body's immune system -- and reduces its ability to fight infections or heal from wounds.
Persistent feelings of sadness can lead to a negative self-image that, in turn, may leave the victim vulnerable to eating disorders like anorexia nervosa. For example, a group of 14 women surveyed by a Norwegian research team reported feeling high levels of self-disgust toward themselves and fear of becoming fat, according to an abstract posted by the National Center for Biotechnology Information. The women, aged 19 to 39, then turned to restrictive eating, purging and body checking to manage these negative emotions. The group sought to release these emotions through such behaviors as anorectic self-control and self-harm, as well as avoiding food- and body-focused situations.
Risk of Self-Harm
The negative emotions associated with sadness frequently express themselves in anxiety and low self-esteem. If these feelings aren't addressed, sufferers may feel more inclined to harm themselves through substance, or suicidal behavior, according to a study due for publication in the Journal of the American Academy of Child and Adolescent Psychiatry's October 2015 issue. Thirty percent of 13,583 high school students surveyed for the National Youth Risk Behavior Survey reported feeling sad two or more times per week. Bullied students were twice as likely to report sadness -- and twice as likely to report suicidal attempts, or thoughts -- as their non-bullied peers.