Allergies are a reaction your body has when exposed to proteins in certain plants, animals, food, etc.
Causes
Food allergy cause: when your immune system mistakes a certain protein in a food as harmful. Your body triggers cells to release chemicals that try to neutralize the food, the next time they eat the food, they will have an allergic reaction.
Seasonal allergy cause: Exposure to pollen is often what causes seasonal allergies.
Symptoms
Some common symptoms are itchy and watery eyes, sneezing, irritated nose, headache, fatigue, sore throat, coughing, itching in the mouth, hives or eczema, swelling, trouble breathing, abdominal pain, dizziness, lightheaded, or fainting.
Prevention
You cannot prevent having allergies but you can prevent having the allergic reaction. To prevent having seasonal allergies you can close your windows and doors and limit your outside time. To prevent food allergies the only thing you can do is not eat the food that contains the proteins.
Treatment
There are multiple ways to stop or slow down an allergic reaction. One is taking medication to counteract the reaction. You can also be immunized with allergy injection therapy. Finally, many people with food allergies carry an Epipen that you inject into the thigh and then go to the hospital.