Anorexia nervosa is an eating disorder characterized by significantly low body weight from dieting and starvation despite feeling fat. It is influenced by pressures like wanting to be skinny from peers and society. Symptoms include being severely underweight, having unusual eating habits, mood swings, and fatigue. Around 1 in 100 people in the US are diagnosed with the disorder each year, with over 1,000 dying annually from complications. Young teenage girls are most at risk. Treatment focuses on cognitive behavioral therapy and other psychotherapy to first cure the mental aspects before addressing physical health.