An autoimmune disorder marked by an inability to digest gluten, a protein in wheat, rye, and barley
Symptoms: Vomiting, abdominal pain and bloating, diarrhea, weight loss, anemia, leg cramps
Mimics: Irritable bowel syndrome, Crohn's disease, cystic fibrosis
Tests: Blood tests can detect high levels of certain antibodies; roughly 10 percent of people with celiac disease, however, test negative for it. Plus: small-intestine-sample biopsy, genetic (DNA) tests.
A complex disorder with a combination of symptoms of unknown cause
Symptoms: Loss of memory or concentration, sore throat, painful lymph nodes in neck or armpits, unexplained muscle and joint pain, extreme exhaustion
Mimics: Sinus problems, hepatitis, fibromyalgia, lupus, rheumatoid arthritis
Tests: No lab or other diagnostic procedures exist to confirm the presence of chronic fatigue syndrome. Diagnosis is based on exclusion of similar disorders.