Gluten, a protein present in wheat and other grains, can produce a range of allergic reactions in those who are sensitive to it, including stuffy or runny noses, skin rashes, lung irritation, and even an anaphylactic, or whole-body, reaction that can lead to death. Because of this, people with gluten allergies should avoid eating foods containing gluten if they want to be free of symptoms. However, not all people experience adverse effects after eating gluten. In fact, research shows that up to 15% of the population may be genetically susceptible to developing celiac disease, an autoimmune disorder caused by a severe reaction to gluten in your digestive system. People with celiac disease cannot properly break down gluten proteins because they have lost the ability to express certain genes responsible for immune function. The result is inflammation of the small intestine, leading to malnutrition and weight loss over time. People with celiac disease need to adhere to a strict gluten-free diet to stay healthy. Gluten is found in most products that contain wheat, barley, rye, oat, spelt, and triticale (a hybrid grain). It also appears as an additive in many processed foods, such as breading, cake mixes, and crackers. If you're wondering whether you have celiac disease, talk to your doctor about getting tested. She or he will conduct a thorough medical history and physical examination to identify signs of gluten sensitivity or allergy.