Why Is Being Underweight Bad?

Anorexia nervosa is a mental health condition characterized by emaciation or extreme thinness, an intense fear of gaining weight and a distorted body image. Eating disorders, such as anorexia nervosa, affect more than 10 million females and 1 million males in the United States, according to the National Eating Disorders Association. Becoming underweight can lead to various health complications, including infertility, neurological and cardiovascular complications, and death.

Infertility and Pregnancy

Women suffering from anorexia nervosa can develop infertility. The body reduces its production of estrogen, which causes amenorrhea or the cessation of menstruation. Without menstruation the uterus cannot properly prepare itself to accommodate a pregnancy. Women who conceive while battling anorexia nervosa have an increased risk of suffering a miscarriage or a cesarean birth and are more likely to suffer from postpartum depression. Although regaining weight reestablishes menstruation for some women, 25 percent remain infertile, according to the University of Maryland Medical Center, or UMMC.

Neurological Complications

Anorexia nervosa patients can develop extensive nerve damage that alters brain and central nervous system function. Seizures, incoherent thinking and peripheral neuropathy have been reported by patients and physicians. The UMMC reports that previous brain scans of anorexic patients showed structural modifications and unusual brain activity, some of which may be permanent regardless of treatment protocols.

Cardiovascular Complications

Severely anorexic patients are more likely to develop heart disease, which is the “most common cause of medical death” among anorexia nervosa patients, according to UMMC. Bradycardia, or a heart rate less than 60 beats per minute, may develop in conjunction with a decreased blood flow, a reduction of cardiac muscle mass and reduced blood pressure. The lack of food or beverage can cause an electrolyte imbalance, or the fluctuation of calcium and potassium, while in an anorexic state. These electrolytes regulate the heart’s electrical activity, which sustains a healthy heart rate and rhythm. Their absence can be life-threatening.

Death

The "American Journal of Psychiatry" published a study in October 2009 that cross-referenced patient records from The Outpatient Eating Disorders Clinic at the University of Minnesota with death records contained in the National Death Index. The findings indicated that 4 percent of 177 anorexia nervosa patients died from health complications, substance abuse, trauma or suicide between 1979 and 1997. The study further reported that suicide rates stemming from eating disorders are higher than those associated with any other mental health disease.