People who have food intolerance may display a range of symptoms, varying significantly in both frequency and severity. Not all people suffering from food intolerance experience all of these symptoms. This range of symptoms makes it difficult to diagnose food intolerance based on these signs alone.
When compared with food allergies, which involve an immune system response, the signs of food intolerance tend to be less severe. For example, unlike with some food allergies, anaphylaxis is not common with food intolerances. The signs of food intolerance may appear immediately after eating the food, or several hours later. In some cases, symptoms may be delayed for up to 48 hours.
Many of the signs of food intolerance are gastrointestinal in nature, such as an upset stomach, cramps, bloating, gas, constipation, or diarrhea. This condition has also been linked to irritable bowel disease. For many people with food intolerance, gastrointestinal symptoms are the only signs that they have food sensitivities.
Other people with food allergies, however, experience additional symptoms. Other signs of food intolerance include headache, dizziness, fatigue, chills, and irritability. Food intolerance may also cause congestion, a runny nose, watering eyes, or asthma-like symptoms, or otherwise affect your respiratory tract. This condition may also affect your skin, causing skin rashes, hives, or eczema.
If you experience any of these potential signs of food intolerance, visit your doctor. Blood tests for food intolerance or an elimination diet may help you pinpoint the cause. After removing that food from your diet, your symptoms should stop.