Celiac disease
“About 83 percent of people with celiac disease are either still undiagnosed or have been misdiagnosed with other conditions,” says Rachel Begun, MS, RDN. “The reason is the symptoms for celiac disease are many and vary widely from person to person.” The symptoms commonly include abdominal pain, constipation, and diarrhea; but people may experience headaches, joint pain, or depression.
“Some people have absolutely no outward symptoms at all, making it particularly hard to diagnose,” says Begun. Celiac disease is most often misdiagnosed as irritable bowel syndrome.