Symptoms of allergies differ depending on the allergen; however, the most common symptoms include headaches, itchiness, rashes, runny nose, wheezing and nausea. Allergens from the air most commonly affect the eyes, nose and lungs, while allergens from food usually affect the mouth, stomach and intestines, notes the American College of Allergy, Asthma and Immunology.
While most allergies only cause discomforting symptoms, severe cases may pose a threat to life, according to Mayo Clinic.
A particularly dangerous reaction is anaphylaxis, which is characterized by loss of consciousness, decrease in blood pressure, rapid weak pulse, lightheadedness, skin rash formation and extreme shortness of breath.
Food allergies may cause varied symptoms, with the most common being tingling mouth, anaphylaxis and swelling of the lips, tongue, face or throat.
Individuals who are allergic to certain drugs may exhibit symptoms such as itchy skin, hives and formation of a rash. Other symptoms include wheezing, facial swelling and anaphylaxis.
Those allergic to insect stings may exhibit symptoms such as swelling around the affected area, coughing, chest tightness, itchy skin, hives, shortness of breath and anaphylaxis.
While most allergy cases resolve on their own, individuals are encouraged to seek immediate medical attention when the symptoms persist or are severe.