Health Impact

Russell's Sign

Russell's sign is the callusing, abrasion, or scarring that can develop on the knuckles when a person repeatedly induces vomiting with their fingers. It is one of the recognized physical signs of bulimia nervosa and other purging behaviors — a visible clue that can prompt earlier recognition and help.

A physical clue to purging — but not a stand-alone diagnosis

Written by the Eating Disorder Facts editorial team Awaiting clinical review by Cindy Hawthorn, MD Updated July 20, 2026

Key takeaways

Russell's sign is thickened, callused, or scarred skin over the knuckles, most often the second and third joints of the hand.
It develops when the teeth repeatedly abrade the back of the hand during self-induced vomiting, over weeks to years.
It is a recognized physical marker of bulimia nervosa and other purging behaviors — a clue for early recognition, though not proof on its own.
Its absence does not rule out an eating disorder: many people purge without ever developing it, including those who vomit without using their hands.
It often heals once purging stops — fresh marks fade within weeks to months, though long-standing scars may persist. Treating the underlying eating disorder is what matters most.

Overview

What is Russell's sign?

Russell's sign refers to calluses, abrasions, small cuts, or scarring on the back of the hand and knuckles that result from repeated self-induced vomiting. Clinically, it appears as thickened, roughened, sometimes hardened (hyperkeratotic) skin, most commonly over the knuckles of the index and middle fingers — the parts of the hand that reach the mouth.

The sign is named after Gerald Russell, the British psychiatrist who first described bulimia nervosa as a distinct diagnosis in 1979 and noted these characteristic hand changes in his patients. Today it remains one of the classic physical findings clinicians are taught to look for.

Mechanism

What causes it

Russell's sign is a mechanical injury. When a person induces vomiting by using their fingers to trigger the gag reflex at the back of the throat, the knuckles repeatedly make contact with the front teeth (the incisors). Over time, that friction and pressure abrade the skin.

With repetition, the body responds the way it does to any recurring friction — by building up protective callus and, eventually, scar tissue. Early on the marks may be red abrasions or small cuts; with months or years of repetition they can become firm calluses, thickened skin, darkened (hyperpigmented) areas, or lasting scars.

Significance

What Russell’s sign indicates

Because the mechanism is so specific, Russell's sign is a meaningful physical clue that a person may be engaging in self-induced vomiting. It is associated with bulimia nervosa, the binge-purge subtype of anorexia nervosa, and purging behaviors that fall under other specified eating disorders.

For clinicians, family members, and individuals themselves, recognizing the sign can open the door to earlier identification and treatment of an eating disorder that is otherwise often hidden. Eating disorders thrive on secrecy, and visible physical signs sometimes prompt the first honest conversation.

What it does not tell you

Important caveats

Russell's sign is a clue, not a diagnosis. Two limits matter:

Its absence does not rule out an eating disorder. Many people who purge never develop it. In particular, those who learn to vomit "hands-free" — without inserting their fingers — typically have no callusing at all. A clean pair of hands says nothing about whether someone is struggling.
Its presence is not proof. Calluses over the knuckles can also come from martial arts, manual labor, certain sports, and some skin conditions. Russell's sign is interpreted in the context of a full clinical picture, never in isolation.

In other words, it can raise concern and prompt a compassionate conversation, but a diagnosis always requires a proper evaluation.

Health context

Is Russell’s sign itself harmful?

The mark on the hand is not dangerous in itself — it is a surface injury. What it points to is the concern. Repeated self-induced vomiting can cause serious harm: erosion of tooth enamel, swollen salivary glands, irritation and damage to the esophagus, and potentially dangerous electrolyte disturbances that affect the heart. If you notice Russell's sign, the priority is not the skin but the behavior behind it and its effects on the body.

Learn more about the effects of bulimia nervosa and the broader warning signs of eating disorders.

Recovery

Does Russell's sign go away?

In many cases, yes. Once purging stops, fresh abrasions and mild redness usually heal within weeks to a few months, like any other skin injury. Longer-standing calluses and scar tissue fade more slowly and, in chronic cases, some residual callus, darkening, or scarring may remain.

If lasting marks are distressing after recovery, dermatologists can offer options ranging from topical treatments to procedures. But the marks themselves are secondary. The meaningful work — and the thing that lets the skin heal in the first place — is recovery from the underlying eating disorder through therapy, medical care, and nutritional support.

Next steps

What to do if you notice it

If you have noticed these marks on your own hands, or on someone you care about, treat it as an invitation to reach out rather than a verdict. Approach the topic with concern rather than accusation, and focus on the person's wellbeing rather than the physical sign.

Eating disorders are treatable, and earlier help leads to better outcomes. Learn how to find specialized treatment and how to support a loved one.

There is hope

A sign on the hands is a reason to reach out.

Eating disorders are treatable, and earlier help leads to better outcomes. A specialized team can guide the way.

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