Celiac disease can be very serious if left untreated, especially in infants. Infants affected by celiac disease usually exhibit symptoms around 6 months old, as they begin to eat solid foods with gluten. Infants and small children go through huge growth in the first few years of life, and failure to absorb necessary nutrients can result in a failure to thrive (the abnormal slowing of the growth and development of an infant resulting from conditions that interfere with normal metabolism, appetite, and activity). Other serious effects on children include weak teeth and bones, stunted or slow growth, and nerve damage.
Adults with celiac disease whose disease is unmanaged may end up suffering malnourishment or cancer. In women particularly, celiac disease may have a devastating affect on their ability to conceive and may cause repeated miscarriages.