Pica Disorder: Causes, Symptoms and Treatment in Adults and Children

Eating things that are not normally considered food can feel confusing, frightening or embarrassing. Many people with pica hide the behaviour because they worry that others will not understand it or that they will be judged.

However, pica is a recognised feeding and eating disorder, not simply a strange habit or a lack of willpower. It can have biological, developmental, psychological and sensory drivers, and effective support starts with understanding why the behaviour is happening.

Pica disorder involves persistently eating non-food, non-nutritive substances (such as soil, chalk, paper or other materials).  To meet diagnostic threshold this needs to be happening regularly for at least one month and when doing so is not appropriate for a person’s developmental stage or part of a culturally accepted practice. Pica is associated with factors including iron deficiency, pregnancy, autism and intellectual disability. Treatment depends on the individual and may include addressing nutritional deficiencies, behavioural or psychological intervention and treating underlying difficulties or deficiencies.

What is pica disorder?

Pica disorder is a feeding and eating disorder characterised by repeatedly eating substances that have little or no nutritional value and would not usually be considered food.

Examples include:

• soil or clay
• chalk
• paper or cardboard
• hair
• wool or string
• paint or plaster
• soap
• starch
• ice.

Under DSM-5-TR diagnostic criteria, the behaviour must have been present for at least one month, be inappropriate for the person’s developmental stage and not form part of a culturally or socially accepted practice.

Pica is generally not diagnosed in children under two because putting objects into the mouth is a normal part of early childhood exploration. In older children and adults, persistent eating of non-food substances should be assessed.

Pica can occur by itself or alongside another developmental, medical or mental health condition. Unlike anorexia nervosa or bulimia nervosa, it is not driven by concerns about body weight or shape.

What causes pica?

There is no single explanation for pica. For some people there is a clear physical factor, while for others the behaviour may have a sensory, behavioural or psychological function.

Nutritional deficiencies

Pica has a particularly well-recognised association with iron deficiency and iron-deficiency anaemia.

Some people with iron deficiency develop strong urges to consume particular non-food substances. One example is pagophagia – compulsively chewing or eating ice.

Research suggests pica can improve or disappear when iron deficiency is treated, although exactly why the two are associated is not fully understood.

Other nutritional deficiencies, including zinc deficiency, may sometimes be relevant. This is why blood tests and nutritional assessment can form an important part of investigating pica.

A specialist dietetic assessment can help identify nutritional concerns and consider how these should be addressed within a wider treatment plan.

Pregnancy

Pica can emerge during pregnancy, sometimes in someone who has never experienced it before.

The reasons are not fully understood, although changes in nutritional requirements and deficiencies such as iron deficiency may contribute.

If you develop cravings for non-food substances during pregnancy, it is important to tell your GP, midwife or another healthcare professional, particularly because some substances may be harmful.

Autism and intellectual disability

Pica occurs more commonly in people with autism and intellectual or developmental disabilities.

For some autistic people, eating or chewing particular materials may provide a sensory experience that feels soothing or regulating. The texture, taste, smell or sensation of an item may be important.

Understanding this function matters. Simply telling someone to stop, without considering what need the behaviour may be meeting, is unlikely to provide an effective long-term solution.

Our work with autistic people and eating difficulties takes account of sensory differences, communication needs and neurodivergence when developing treatment.

Psychological and emotional factors

For some people, pica appears to become associated with stress, anxiety, boredom or emotional distress.

The behaviour may feel calming, comforting or compulsive and can become an established way of regulating difficult feelings.

A psychological assessment can explore when the behaviour happens, what tends to trigger it and what function it may be serving.

Pica in adults

Although pica is often associated with childhood or pregnancy, pica in adults can occur at any stage of life.

Adults experiencing pica may feel particularly isolated because the problem is rarely talked about. Some people live with the behaviour privately for months or years before seeking help.

Pica eating disorder in adults can present in different ways. Someone might compulsively chew ice, eat paper or chalk, consume soil or clay, or repeatedly feel drawn towards another non-food substance.

Possible factors include:

• iron or another nutritional deficiency
• pregnancy
• autism or intellectual disability
• sensory-seeking behaviour
• stress or emotional regulation
• other mental health or developmental difficulties.

If you are experiencing pica, it is worth mentioning the behaviour explicitly to a healthcare professional, even if it feels embarrassing. Pica is a recognised condition and warrants proper assessment rather than shame.

Signs of pica in toddlers and children

Very young children naturally explore their environment by putting things into their mouths. For that reason, pica is generally not diagnosed in children under two.

Possible signs of pica in a toddler or older child include persistently seeking out and eating non-food substances such as soil, chalk, paper, paint, plaster, hair or fabric, particularly when the behaviour continues beyond the developmental stage when mouthing objects would usually be expected.

Parents might notice that a child:

• repeatedly seeks out the same non-food substance
• eats soil, sand, chalk, paper or other objects rather than simply mouthing them
• hides or collects particular items to eat
• repeatedly returns to the behaviour despite attempts to prevent it
• develops constipation, abdominal pain, dental problems or other unexplained physical symptoms.

If you are unsure whether something is normal childhood exploration or pica, professional advice can help establish whether further assessment is needed.

What are the health risks of pica?

The risks depend greatly on what someone is eating, how much they consume and how frequently it happens.

Possible complications include:

Poisoning. Eating substances containing lead or other toxins, such as some paints or contaminated soil, can cause poisoning.

Bowel obstruction or damage. Materials that cannot be digested may accumulate in the gastrointestinal tract and, in severe cases, cause a blockage or other complications.

Infection or parasites. Eating contaminated soil or other materials can expose someone to harmful organisms.

Dental damage. Regularly chewing hard or abrasive substances, including ice or stones, can damage teeth.

Choking. Some objects present an immediate choking risk.

Nutritional deficiencies can also coexist with pica. These risks are why persistent pica should not simply be ignored, even if the person otherwise feels well.

When to seek help for pica

Consider arranging an assessment if:

• you or your child repeatedly eats non-food substances
• the behaviour has continued for a month or longer
• you feel unable to control an urge to eat a particular substance
• the behaviour is being hidden because of shame or embarrassment
• you are pregnant and have developed cravings for non-food substances
• there may be an underlying nutritional deficiency
• pica occurs alongside autism, intellectual disability or another developmental condition
• the behaviour is causing dental, gastrointestinal or other physical problems.

Urgent medical help should be sought if someone may have swallowed something poisonous or dangerous, is choking, has severe abdominal pain or vomiting, or develops symptoms suggesting an intestinal blockage or another acute medical problem.

How is pica diagnosed and treated in the UK?

Getting a diagnosis for pica

Diagnosis begins with a clinical assessment of what the person is eating, how frequently it happens, how long it has been happening and what may be driving the behaviour.

A clinician will also consider the person’s physical and mental health, developmental history and any other feeding or eating difficulties.

Medical investigations may be recommended, including blood tests for iron deficiency and other nutritional problems, alongside tests for complications relating to the particular substance being eaten.

Our guide to how feeding and eating disorders are diagnosed explains more about specialist assessment.

What kind of professionals treat pica disorder?

Because pica can have both physical and psychological causes and consequences, treatment may involve several different healthcare professionals.

Depending on the individual, this can include:

• a psychologist or specialist psychological therapist
• a dietitian
• a psychiatrist
• a GP, paediatrician or other medical professional.

At The London Centre, our multidisciplinary approach enables psychological, dietetic and psychiatric perspectives to be brought together where required rather than viewing the eating behaviour in isolation.

Where broader mental health difficulties are relevant, specialist psychiatric assessment and treatment can also form part of someone’s care.

Treating nutritional deficiencies

Where iron or another deficiency is identified, this needs appropriate medical treatment.

In some people with iron-deficiency-related pica, treating the deficiency substantially reduces or stops the urge to eat non-food substances.

However, not everyone with pica has a nutritional deficiency, so normal blood tests do not mean the behaviour should be dismissed.

Behavioural and psychological treatment

Therapy for pica is individually tailored because the reasons behind the behaviour vary.

Behavioural approaches may focus on identifying triggers, reducing access to unsafe materials, developing alternative behaviours and reinforcing safer responses.

For adults whose pica is linked to stress, emotional regulation or other psychological difficulties, therapy can also help them understand the function the behaviour serves and develop alternative ways of meeting those needs.

When autism or intellectual disability is present, treatment should be appropriately adapted and may include consideration of sensory needs and support from family members or carers.

The evidence base for specific psychological treatments for pica remains more limited than for some other eating disorders, making careful individual assessment particularly important.

People experiencing other feeding difficulties alongside pica may also benefit from input from our specialists in ARFID and related feeding disorders.

Can pica be treated online?

Some aspects of assessment and psychological treatment may be delivered remotely where clinically appropriate, although medical investigations such as blood tests still need to be arranged in person.

The London Centre provides online consultations and specialist remote therapy for people who cannot easily attend one of our clinics.

This can allow treatment to take place within everyday life while still drawing on specialist eating-disorder expertise.

Getting specialist help for pica

Pica is treatable, and seeking help does not mean that you have done anything wrong.

Often the first steps are straightforward: talking openly about what you have been eating, checking whether nutritional or medical factors may be contributing and understanding what purpose the behaviour may be serving.

The London Centre for Eating Disorders and Body Image provides specialist assessment and treatment for feeding and eating difficulties in adults and young people. Depending on your needs, support can draw on psychological, dietetic and psychiatric expertise and may be offered in person or remotely.

If you are worried about your own behaviour or are supporting a child or adult who may have pica, you can contact our team confidentially to discuss the most appropriate first step.

Frequently asked questions about pica

Can pica go away on its own?

Sometimes. Pica may resolve when an underlying factor changes – for example, when an associated iron deficiency is treated – and some childhood pica is temporary. Persistent pica should nevertheless be assessed, particularly where the substance being eaten could cause harm.

Does pica always mean a nutritional deficiency?

No. Iron deficiency has a strong association with pica, but pica can also occur during pregnancy and alongside autism, intellectual disability, sensory differences or psychological difficulties. Assessment should therefore consider the whole picture rather than relying on blood tests alone.

Is pica a mental health condition or a physical condition?

Pica sits across both physical and psychological healthcare. It is classified as a feeding and eating disorder, but physical factors such as iron deficiency may be associated with it and the behaviour itself can cause medical complications. For this reason, treatment may require medical, dietetic and psychological input.