There is evidence that a combination of genetics and environmental factors may play a role in your allergies. While the exact genetic (inherited) factors are not yet understood, the tendency to allergies, as well as to allergic disease, is linked to heredity. Additionally, people with certain medical conditions have been linked to allergies. People with medical conditions such as asthma or other lung conditions that affect breathing, frequent infections of the nasal sinuses, ears, or respiratory tract, eczema or sensitive skin, are more likely to develop and/or have allergies. Further, your surrounding environment may aggravate your allergies: the more intense and repetitive your exposure is to allergens and the earlier in life it occurs, the more likely it is that an allergy will develop.