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Bulimia’s Effects on the Knuckles and Hands

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Although bulimia nervosa (BN) is an insidious disease, usually characterized by secretive behavior to mask the disorder, there are some telltale signs that others can watch for when concerned about someone close to them. Bulimia symptoms are not always obvious – they include behaviors like hiding food, avoiding confrontation about their eating habits, binging in private, and self-isolating. Most harmful effects to the body are happening internally – such as malnutrition, loss of muscle mass, and harmful lesions of the digestive tract, as well as a decline in mental health. 

Education about the outward signs of bulimia and purging are more noticeable and include signs like tooth decay and damage to the hands and knuckles from purging.

Bulimia’s Effects on the Knuckles and Hands

What is Russell’s Sign?

Russell’s sign is a pattern of calluses on the knuckles or back of the hand due to repetitive self-induced vomiting over a long period of time, and is a key indicator of bulimia nervosa. The individual develops “bulimia knuckles” by using their fingers to trigger a gag reflex, causing scrapes on the back of the hand or knuckles from the incisor teeth. The British psychiatrist Gerald Russell first recognized this sign as a common indicator among his eating disorder patients, hence the name. (1) Just as bulimia nervosa and other eating disorders can affect all genders and ethnicities, Russell’s sign can also be present on any person. 

Although bulimia nervosa is usually thought of as associated with oral purging – purging does not always mean vomiting. Purging can also take place in the form of diuretic or laxative abuse, or a mixed presentation. Because of this, Russell’s sign cannot be used as a sole method of diagnosing or confirming the presence of bulimia.

It should also be noted that only those who use their hand to induce a gag reflex to purge through vomiting develop this sign of “bulimia knuckles.” Many who purge may use an object, such as a toothbrush handle or straw to trigger the gag reflex, and some bulimic patients are capable of "hands free purging” over time, meaning that they can induce vomiting without external triggering of the gag reflex. Thus, the absence of Russel’s sign does not exclude the possibility that an individual is engaging in purging.

How serious is Russell’s sign?

Of the physical characteristics related to bulimia and purging, Russell’s sign is a fairly late one, indicating that someone is undergoing a more advanced stage of the disease as they are purging frequently enough to induce callouses on the back of the hand. Thus, it may be a sign in particularly advanced disease or in patients with very serious, persistent purging behaviors.

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Other Physical Signs of Purging 

One of the first signs is usually a decline in oral health, with discolored or stained teeth and more frequent cavities. This is caused by frequent contact with stomach acids. Next can be swelling around the cheeks and jawline, which is caused by forceful, repeated vomiting. Russell’s sign is usually one of the later signs, which indicates especially frequent vomiting, which re-injures the same area without a chance for it to heal between purges.

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Is This Effect Permanent?

The good news is that Russell’s sign is just that – a sign. It does not cause permanent harm to the hands and knuckles. The internal metabolic effects of purging can cause more lasting damage.

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What To Do About A Russel’s Sign 

Recovery from bulimia nervosa is an emotional journey, and above all, support is needed. It is important to understand that the physical signs of bulimia are only the visible part of a mental health condition that affects every facet of a person’s life. (1) At Within Health we offer virtual treatment programs for patients with eating disorders like bulimia nervosa. Speak to our admissions team today to learn how to get started.

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Frequently asked questions


  1. Barry, C. (2021). What is Russell's Sign l Understanding Russell's Sign. Retrieved 31 January 2022, from
  2. Eating Disorders: About More Than Food. (2022). Retrieved 1 February 2022, from
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