What Is Pica? A Guide to a Little-Understood Eating Disorder

Pica is a complex and often misunderstood eating disorder characterized by the persistent consumption of non-food substances. While many people may have heard the term in passing—or encountered it in medical or psychological contexts—few fully understand what pica is, why it occurs, who it affects, and how it is treated.

Defining Pica

Pica is an eating disorder in which an individual repeatedly eats substances that have no nutritional value and are not considered food. Common examples include dirt, clay, chalk, ice, paper, soap, hair, paint chips, metal, or stones. To meet diagnostic criteria, this behavior must persist for at least one month and be inappropriate for the individual’s developmental level.

The term pica comes from the Latin word for magpie (Pica pica), a bird known for eating almost anything. The name reflects the indiscriminate nature of the substances consumed by people with this condition.

Importantly, pica is not simply curiosity, experimentation, or a one-time event. It is a repeated, compulsive behavior that can pose serious health risks and often signals underlying medical, psychological, or social issues.

Who Does Pica Affect?

Pica can affect people of all ages, genders, and backgrounds, but it is more commonly observed in certain populations.

Children

Pica is most frequently diagnosed in young children, particularly toddlers and preschoolers. While mouthing objects is developmentally normal in infants, pica involves persistent ingestion beyond the age at which such behavior is expected to stop. In children, pica may be associated with developmental delays, autism spectrum disorder, or intellectual disability.

Pregnant Individuals

Pregnant people are another group in which pica is relatively common. Cravings for substances such as ice, clay, starch, or dirt have been documented across cultures. These cravings are sometimes linked to nutritional deficiencies, particularly iron deficiency.

Individuals With Developmental or Intellectual Disabilities

Pica is more prevalent among people with intellectual disabilities or neurodevelopmental conditions. In these cases, pica may be associated with sensory-seeking behaviors, difficulty distinguishing food from non-food items, or difficulties with impulse control.

Although less common, pica does occur in adults without developmental disabilities. In adults, it is often associated with nutritional deficiencies, mental health conditions, stress, trauma, or cultural practices.

Common Substances Consumed in Pica

The substances consumed in pica vary widely. Some of the most commonly reported include:

• Earth substances: dirt (geophagia), clay, sand

• Ice: compulsive ice chewing (pagophagia)

• Starch: laundry starch, cornstarch (amylophagia)

• Paper products: paper, cardboard, toilet paper

• Chalk or plaster

• Hair: leading to hairballs (trichophagia)

• Paint chips: particularly dangerous due to lead exposure

• Soap, detergent, or cleaning products

• Metal objects or stones

The specific substance may offer clues about underlying causes, such as mineral deficiencies or sensory preferences.

Causes and Risk Factors

There is no single cause of pica. Instead, it appears to result from a combination of biological, psychological, social, and cultural factors.

Nutritional Deficiencies

One of the most well-established links is between pica and mineral deficiencies, especially iron and zinc. For example, pagophagia (ice eating) is strongly associated with iron-deficiency anemia. In some cases, treating the deficiency reduces or eliminates pica behaviors.

Psychological and Mental Health Factors

Pica has been associated with several mental health conditions, including:

• Obsessive-compulsive disorder (OCD)

• Autism spectrum disorder

• Intellectual disability

• Schizophrenia

• Depression and anxiety

In these cases, pica may function as a coping mechanism, a compulsive behavior, or a form of sensory regulation.

Developmental Factors

Children explore their environment through their mouths, but pica is diagnosed when this behavior continues beyond a developmentally appropriate age. Delays in cognitive or emotional development increase the risk.

Cultural and Social Influences

In some cultures, eating clay or soil is a traditional practice, particularly during pregnancy. While culturally sanctioned behaviors are not automatically considered pica, they may still pose health risks depending on the substances consumed.

Stress, Trauma, and Neglect

Stressful environments, trauma, poverty, neglect, or lack of supervision can contribute to the development of pica. In some cases, pica may reflect unmet emotional or physical needs.

Signs and Symptoms

The most obvious sign of pica is the repeated consumption of non-food items. However, additional symptoms may arise depending on what is consumed and for how long.

Behavioral Signs

• Persistent cravings for non-food substances

• Hiding or hoarding non-food items

• Eating unusual items despite attempts to stop

• Resistance or distress when prevented from eating these substances

Physical Symptoms

• Abdominal pain or bloating

• Constipation or diarrhea

• Dental damage

• Nausea or vomiting

• Fatigue (especially if anemia is present)

Serious Complications

• Intestinal blockage or perforation

• Heavy metal poisoning (e.g., lead)

• Parasitic infections

• Choking or airway obstruction

Because many people feel embarrassed or fear judgment, pica behaviors are often hidden, which can delay diagnosis and treatment.

Health Risks and Complications

Pica is not merely an unusual habit; it can be dangerous and, in severe cases, life-threatening.

Toxicity and Poisoning

Consuming paint chips, soil, or metal can expose individuals to lead, mercury, or other toxins. Lead poisoning, in particular, can cause neurological damage, especially in children.

Gastrointestinal Problems

Non-food items can cause intestinal blockages, tears, or infections. Hair ingestion can lead to trichobezoars—large hairballs that may require surgical removal.

Nutritional Consequences

Ironically, pica can exacerbate nutritional deficiencies by disrupting normal eating patterns or damaging the digestive system.

Dental and Oral Damage

Hard or abrasive substances like stones, metal, or ice can crack teeth, damage gums, and cause chronic oral pain.

Diagnosis of Pica

Diagnosing pica typically involves a combination of clinical interviews, medical evaluations, and behavioral assessments.

Diagnostic Criteria

According to diagnostic guidelines, pica is diagnosed when:

• Non-food substances are eaten persistently for at least one month

• The behavior is inappropriate for the individual’s developmental level

• The behavior is not culturally sanctioned

• The behavior is severe enough to warrant clinical attention

Medical Evaluation

Healthcare providers may order blood tests to assess iron, zinc, or other deficiencies, and imaging studies if an intestinal obstruction is suspected.

Psychological Assessment

A mental health professional may assess for underlying conditions such as OCD, autism, or trauma-related disorders.

Treatment and Management

Treatment for pica depends on the individual’s age, underlying causes, and the substances involved. There is no one-size-fits-all approach.

Treating Nutritional Deficiencies

If iron or zinc deficiency is identified, supplementation often significantly reduces pica behaviors.

Behavioral Interventions

Behavioral therapies are particularly effective in children and individuals with developmental disabilities. These may include:

• Positive reinforcement for appropriate eating

• Environmental modifications to limit access to non-food items

• Teaching alternative behaviors

Psychological Therapy

For individuals with mental health conditions, cognitive-behavioral therapy (CBT) or other forms of psychotherapy may help address compulsive behaviors, stress, or trauma.

Medical Monitoring

In severe cases, ongoing medical supervision is necessary to prevent complications and manage risks.

Family and Caregiver Education

Educating caregivers about pica, its risks, and management strategies is a critical component of treatment.

Pica Across Cultures and History

Pica has been documented throughout history and across cultures. Ancient medical texts reference cravings for earth and clay, particularly during pregnancy. In some regions, geophagia remains a traditional practice believed to alleviate nausea or provide minerals.

Modern medicine distinguishes between culturally accepted practices and pathological pica, but both require careful consideration of health risks.

Living With and Supporting Someone With Pica

Supporting someone with pica requires patience, understanding, and a non-judgmental approach. Shaming or punishment is ineffective and can worsen the behavior. Instead, effective support focuses on safety, medical care, and addressing underlying needs.

Key strategies include:

• Removing or limiting access to dangerous substances

• Encouraging medical and psychological evaluation

• Maintaining open communication

• Celebrating progress rather than focusing on setbacks

Summary

Pica is a serious and complex eating disorder defined by the persistent consumption of non-food substances. While it may appear strange or baffling, pica often serves as a signal of deeper nutritional, psychological, developmental, or social issues. Left untreated, it can lead to significant health risks, but with proper diagnosis and individualized treatment, many people experience substantial improvement.

Understanding what pica is—and what it is not—is essential for reducing stigma, promoting early intervention, and ensuring compassionate, effective care. Whether occurring in a child, a pregnant individual, or an adult, pica deserves careful attention, medical evaluation, and thoughtful support.