Which of the following is least characteristic of anorexia nervosa – a) Lowered vital signs when the weight is low b) Decreased physical activity c) history of obestity d) Denial of illness

**Core Concept**
Anorexia nervosa is a complex eating disorder characterized by a distorted body image, restrictive eating patterns, and excessive weight loss. It involves a combination of psychological, emotional, and physiological factors.

**Why the Correct Answer is Right**
Anorexia nervosa often presents with a constellation of physical and behavioral symptoms, including:
* Lowered vital signs (e.g., bradycardia, hypotension) when weight is low, due to malnutrition and dehydration (**Option A**).
* Decreased physical activity, as individuals with anorexia nervosa may avoid exercise or physical activity due to fear of weight gain (**Option B**).
* Denial of illness, a common feature of anorexia nervosa, as individuals may resist treatment and deny the severity of their condition (**Option D**).

**Why Each Wrong Option is Incorrect**
**Option C:** A history of obesity is not characteristic of anorexia nervosa. In fact, individuals with anorexia nervosa typically have a low body mass index (BMI) and may have a history of restrictive eating patterns or dieting.

**Clinical Pearl / High-Yield Fact**
A key feature of anorexia nervosa is the presence of amenorrhea (loss of menstrual cycle), which is often used as a diagnostic criterion. This is due to the significant weight loss and nutritional deficiencies that disrupt hypothalamic-pituitary-gonadal axis function.

**Correct Answer: C. A history of obesity is not characteristic of anorexia nervosa.**