Dietary intolerance refers to an individual's inability to digest or tolerate certain foods, resulting in adverse reactions when consumed. This can be due to a lack of specific enzymes required for the breakdown and absorption of particular nutrients, or sensitivity to certain ingredients such as lactose, gluten or artificial additives. Symptoms may include bloating, gas, diarrhea, abdominal pain, skin rashes, headaches, joint pain or fatigue, and can range from mild to severe depending on the individual's sensitivity level. Avoiding the offending food(s) is typically necessary for managing dietary intolerance, although in some cases medical intervention may be required.