Bulimia nervosa, often simply called bulimia, is a serious eating disorder characterised by a recurring cycle of binge eating (consuming a large amount of food in a short period with a sense of loss of control) followed by compensatory behaviours aimed at preventing weight gain. These behaviours can include:

• Self-induced vomiting: This is one of the most well-known compensatory behaviours.
• Misuse of laxatives, diuretics, or enemas: These are used in an attempt to eliminate calories from the body.
• Fasting Periods of severe calorie restriction after a binge.
• Excessive exercise: Exercising to an extreme degree to "burn off" the calories consumed during a binge.

Key characteristics of bulimia nervosa:

• Recurrent episodes of binge eating: Eating an amount of food that is definitely larger than what most people would eat in a similar period of time under similar circumstances, accompanied by a sense of lack of control over eating during the episode.

• Recurrent inappropriate compensatory behaviours to prevent weight gain.
• The binge eating and compensatory behaviours both occur, on average, at least once a week for three months.

• Self-evaluation is unduly influenced by body shape and weight. This means a person's sense of self-worth is excessively tied to their size and weight.
• The disturbance does not occur exclusively during episodes of anorexia nervosa. This is a key differentiator from the binge-eating/purging subtype of anorexia, where the individual is significantly underweight. Individuals with bulimia are often at a normal weight or overweight.

Important aspects of bulimia nervosa:

• Secrecy and Shame: Individuals with bulimia often feel intense shame and guilt about their binge eating and compensatory behaviours, leading them to engage in these activities in secret.
• Distorted Body Image: While not the primary diagnostic feature as in anorexia, individuals with bulimia often have a significant dissatisfaction with their body shape and weight.
• Cycle of Behaviour: The binge-purge cycle can become compulsive and is often used as a way to cope with negative emotions or stress. However, it typically leads to more guilt and anxiety, perpetuating the cycle.
• Physical Consequences: Repeated purging behaviours can lead to a range of serious physical health problems, including electrolyte imbalances, dental problems (due to stomach acid from vomiting), esophageal damage, gastrointestinal issues, and heart problems.
• Co-occurring Mental Health Conditions: Bulimia frequently occurs alongside other mental health conditions such as anxiety disorders, depression, and substance use disorders.

It's crucial to understand that bulimia nervosa is a serious mental illness that requires professional help. Treatment typically involves a combination of psychotherapy (such as cognitive behavioural therapy or family-based therapy), nutritional counselling, and sometimes medication.   Early intervention significantly improves the chances of recovery.