Pica is dangerous because the non-food items people consume can poison the body, block or tear the digestive tract, introduce parasites, and worsen nutritional deficiencies. The risks depend on what’s being eaten and how long the behavior continues, but some complications are life-threatening and require emergency surgery.
Pica is the persistent eating of non-food substances like dirt, clay, paint chips, hair, or ice for a month or longer. It’s not diagnosed in children under two, since mouthing objects is a normal part of development at that age. But beyond toddlerhood, in older children, pregnant women, and adults with developmental or mental health conditions, the habit carries real and sometimes severe health consequences.
Digestive Blockages and Internal Damage
The most immediately dangerous complication is a physical obstruction in the digestive tract. Items like hair, coins, stones, or small magnets can clump together into masses that block the small or large intestine. Hair is a particularly common culprit: it doesn’t break down in stomach acid, so over time it forms dense, matted balls that get stuck and prevent food from passing through. Symptoms include belly pain, nausea, bloating, and vomiting.
Sharp or rough objects pose a different threat. They can lacerate the lining of the esophagus, stomach, or intestines, potentially causing a perforation, which is a hole in the digestive wall. A perforated bowel is a surgical emergency. Small magnetic toys are especially hazardous for children because multiple magnets can attract each other through the walls of different sections of intestine, pinching tissue between them and cutting off blood flow. These scenarios often end in the operating room.
Lead Poisoning and Chemical Toxicity
When pica involves eating paint chips, soil, or other contaminated materials, heavy metal poisoning becomes a serious concern. Lead exposure is the most well-documented risk, especially in children. Even low levels of lead in the blood damage a child’s brain and nervous system, leading to lower IQ, decreased ability to pay attention, underperformance in school, and hearing and speech problems. These effects on growth and cognitive development can be permanent.
Other substances carry their own chemical hazards. Clay and soil may contain pesticides, fertilizers, or industrial contaminants. Items like batteries, cleaning products, or certain plastics introduce toxins the body isn’t equipped to process. The danger scales with the amount consumed and the duration of the behavior, but even small, repeated exposures to toxic materials accumulate over time.
Parasitic and Bacterial Infections
Eating soil or dirt, a form of pica called geophagia, exposes people to parasites that live in contaminated ground. One of the most common is Toxocara, a roundworm parasite spread through dog and cat feces. The eggs survive in soil and enter the body when contaminated dirt is swallowed. Young children who play in or eat dirt are at highest risk.
Toxocara infection takes two main forms. Visceral toxocariasis occurs when the parasite migrates into organs like the liver or central nervous system, causing fever, coughing, wheezing, abdominal pain, and liver enlargement. Ocular toxocariasis happens when the parasite reaches the eye, where it can cause inflammation, retinal damage, and vision loss, typically in just one eye. Soil-based pica has also been linked to toxoplasmosis and other parasitic infections that can cause lasting organ damage.
Worsening Nutritional Deficiencies
Pica and iron deficiency have a complicated, two-way relationship. Iron deficiency anemia is one of the most common conditions associated with pica, and for years researchers debated whether the deficiency triggers the cravings or the cravings worsen the deficiency. The answer appears to be both.
When someone eats clay or soil, the earth particles actually bind to dietary iron in the gut, making it harder for the body to absorb. The soil essentially coats the intestinal lining in a way that blocks normal nutrient uptake. So a person who already has low iron and begins eating dirt in response to cravings ends up absorbing even less iron from their food, deepening the deficiency. This creates a cycle that’s difficult to break without treating both the pica behavior and the underlying nutritional problem.
Risks During Pregnancy
Pica is remarkably common in pregnancy. One study found a prevalence of 50% among pregnant women surveyed. The consequences extend beyond the mother’s health to the developing baby. Women who practiced pica during pregnancy had significantly lower hemoglobin levels (indicating worse anemia), higher rates of preterm labor, and their newborns had lower birth weights and lower Apgar scores, which measure a baby’s immediate health after delivery.
The mechanism is straightforward: if pica reduces iron absorption or introduces toxins during a period when nutritional demands are already high, both the mother and fetus pay the price. Anemia during pregnancy increases the risk of complications during delivery, and low birth weight is one of the strongest predictors of health problems in a newborn’s first year of life.
Damage to Teeth and Mouth
The dental effects of pica are often overlooked but can be extensive. Chewing on rocks, metal, ice, or other hard or abrasive materials wears down tooth enamel in patterns that don’t match normal wear. Teeth develop cupping and grooves in the underlying dentin, with sharp enamel edges left behind. Over time, this leads to fractures, increased sensitivity, and the need for dental repair.
Sharp or rough items also cause repeated cuts and ulcers inside the mouth, gum recession, and jaw joint problems. Poor oral hygiene often accompanies chronic pica, accelerating gum disease. Staining of the teeth and inner cheeks is common with certain substances like clay or chalk. For dental professionals, these patterns can actually be the first visible sign that someone has pica, making routine dental visits an unexpected but important point of detection.