| General systemic | Adults: lassitude, inanition, depression, fatigue, irritability, general malnutrition with or without weight loss |
| Children: irritability, fretfulness, emotional withdrawal or excessive dependence, nausea, anorexia, malnutrition with protruberant abdomen, muscle wasting of buttocks, thighs and proximal arms; with or without vomiting and diarrhea |
| Skin and mucous membranes | Aphthous stomatitis (recurrent) |
| Angular cheilitis |
| Atopic dermatitis (persistent or recurrent) |
| Dermatitis herpetiformis (in 5 percent of patients with celiac disease) |
| Alopecia areata (especially alopecia universalis) |
| Melanosis (chloasma bronzium) |
| Erythema nodosum |
| Skeletal system | Osteoporosis/osteopenia (in 100 percent of patients with celiac disease) |
| Dental enamel defects |
| Short stature |
| Arthritis or arthralgia (central arthritis-sacroiliitis in 63 percent of patients with celiac disease) |
| Bone pain, especially nocturnal |
| Hematologic system | Anemia (iron deficiency is the most common cause), folic acid deficiency in 10 to 40 percent of children and 90 percent of adults; B12 deficiency (rare) |
| Leukopenia, coagulopathy and thrombocytosis. |
| Gastrointestinal system | Diarrhea in 60 percent of patients (small intestinal type), early diarrhea occurs with infrequent, large, watery, foul stools; later diarrhea occurs more frequently |
| Constipation in 20 percent of patients, with occasional obstipation and pseudo-obstruction |
| Lactose intolerance in 50 percent of patients with gastrointestinal symptoms |
| Anorexia, nausea, vomiting, abdominal pain and bloating |
| Pancreatitis, hepatitis, lymphoma |
| Immune system | Associated autoimmune diseases: |
| Diabetes mellitus type 1 |
| Thyroid disease |
| Sjögren's syndrome |
| Collagen disorders |
| Rheumatoid arthritis |
| Liver disease |
| Selective IgA deficiency |
| Reproductive system | Delayed puberty |
| Infertility |
| Neurologic system | Seizures, with or without occipital calcification |
| Unexplained neuropathic illnesses, including ataxia and peripheral neuropathies |
| Dementia |
| Other associated conditions | Down syndrome |
| IgA nephropathy |
| Fibrosing alveolitis of the lung |
| Hyposplenism, with atrophy of the spleen |