If you never had allergies as a kid or a teen, then you may think that you get to cruise through life allergy free. An allergy develops when your immune system mistakes a harmless substance for a dangerous invader. This can cause a variety of allergic reactions ranging from the innocuous to the significant — a mild skin irritation to trouble breathing. Allergic reactions can be caused by anything from food to dust and dander. More and more adults are beginning to develop allergies. Although the exact reasons and causes as to why allergies develop later in life are unknown, there are a few common reasons that cause the most speculation.

1. You usually develop allergies either during your early elementary school years or during early adulthood. It’s much more common to develop allergies in your 20s than in your 30s or later. One reason could be that as a child you are exposed to more allergens and so your immune system is used to them. As an adult, you may not be exposed to as many outside allergens, which is why you begin sneezing and suffering when you finally get outdoors.

2. If you’re just noticing your allergies, it’s possible that they aren’t new, you’re just starting to notice them. Your allergies could have been mild at first but have suddenly gotten much worse and so you notice itchy, runny eyes and a stuffy nose. Moving to a new environment can cause the change — maybe your new home has more pollution or different trees than you are used to being around.

3. It’s possible that your allergies aren’t actually allergies, but a mild cold, sinus infection or other similar symptoms. If you are concerned about allergies, then you can be tested to find out your allergens. Allergies commonly dissipate later in life, although your immune system can weaken, leaving you more open to infection.

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