[3] Pica's medical definition refers to the persistent consumption of nonnutritive substances, ice in this case, for over a period of at least one month.
"[4] It has been shown to be associated with iron-deficiency anemia[5] and responsive to iron supplementation,[6][7] leading some investigators to postulate that some forms of pica may be the result of nutritional deficiency.
[8] Similarly, folk wisdom also maintained that pica reflected an appetite to compensate for nutritional deficiencies, such as low iron or zinc.
[9] A hypothesis of the neurological basis of pagophagia was proposed in a 2014 study in which those with iron deficiency anemia were shown to have improved response times while performing on a neuropsychological test when given ice to chew on.
[10] Although some investigators[8] also hypothesize that chewing ice may lessen pain in glossitis and stomatitis related to iron-deficiency anemia, the specific pathophysiology is still unknown and this hypothesis remains controversial.
[13] Since a common underlying cause of pagophagia is iron-deficiency anemia, many people with the disorder will also experience weakness, fatigue, pallor, sore tongue, dizziness, headache, and cold extremities.
[medical citation needed] Other symptoms associated with iron deficiency may include brittle nails, cracking at the corner of the mouth, and restless legs syndrome.
[14] Severe cases of iron deficiency can also cause the body to make up for decreased oxygen-carrying capacity of the blood by increasing cardiac output.
[16] Although compulsive consumption of ice is frequently associated with a deficiency of iron, the exact etiology of this form of pica is not well-understood.
In support of this hypothesis, individuals with iron-deficient anemia were found to have improved response times on neuropsychological tests than compared to healthy controls when chewing ice.
[14] In another case, a woman with iron-deficiency anemia related to gynecological bleeding was admitted and her dietary screening showed consumption of about 80 ice cubes for day for the past 5 years.
[16] Some suggestions for other causes of pagophagia include hunger and gastrointestinal distress related to ways the body attempts to ease the stress.
[20] Pagophagia may often go undiagnosed as those with the condition may consider it to be harmless and not seek medical help unless the behavior begins to interfere with their lives.
Screening for pagophagia may help clinicians gather valuable information towards the diagnosis and treatment, especially populations who are at risk, for iron deficiency.
Women who are menstruating, pregnant, or lactating may benefit from pagophagia screening because of the high occurrence of iron deficiency in these groups.
[28] A study of pica in pregnant Mexican-born women living in either the United States or Mexico found differing rates of pagophagy between the two groups.