When you have allergies, your body overreacts to things that don’t bother most people. Your immune system mistakes the harmless substances for dangerous invaders and releases chemicals to fight them. This causes your symptoms.
You may be more likely to have allergies if they run in your family. Asthma, hay fever, and eczema often occur together. If you have one of these conditions, you’re more likely to have the others.
Your environment also plays a role. If you live in an industrialized country, you’re more likely to have allergies than if you live in a developing country. This may be because people in industrialized countries are exposed to more allergens, such as pollutants and chemicals.
You’re also more likely to have allergies if you’re exposed to them at an early age. If you have allergies, your symptoms may get worse when you’re around the things you’re allergic to (allergens). Allergens can be found in the air, dust, food, and insects.
Your symptoms may also vary depending on the time of year. For example, if you’re allergic to pollen, you may have more symptoms in the spring when pollen counts are high.
Allergies can cause a wide range of symptoms. They may be mild, moderate, or severe. They can also come and go.
Mild symptoms may include:
A runny nose
Red, itchy eyes
Itchy throat or nose
Moderate symptoms may include:
A runny nose
Shortness of breath
Severe symptoms may include:
Severe wheezing or difficulty breathing
Swelling in the face, throat, or tongue
Dizziness, lightheadedness, or fainting
Pale or blue skin
Hives (red, itchy bumps on the skin)
Anaphylaxis (a severe, potentially life-threatening allergic reaction)
If you have any of these symptoms, call 911 or go to the nearest emergency room. Anaphylaxis is a medical emergency.