There are different types of asthma, and they are classified based on the triggers. A few of the types include:   • Allergic asthma Allergic asthma is one of the most common forms of asthma. Many who suffer from allergic asthma also suffer from other allergic conditions, including food allergies, eczema, and allergic rhinitis.   • Non-allergic asthma Non-allergic asthma does not require an allergic trigger or cause a flare-up for an attack to occur. While it is less common than allergic asthma, it still happens to many worldwide every year, and it is believed that non-allergic asthma develops due to environmental and genetic factors.   • Seasonal asthma Flare-ups from seasonal asthma occur under certain conditions or during certain times of the year.   • Occupational asthma Symptoms of occupational asthma become worse when working, or the symptoms improve when not working.   • Exercise-induced asthma Exercise-induced asthma is triggered either during or immediately after exercise or other strenuous activity.   • Difficult-to-control asthma Many do not believe difficult-to-control asthma should be a subtype or even a diagnosis. However, there are some whose symptoms are harder to manage, as they happen frequently, or they have life-threatening asthma attacks.   • Severe asthma To be considered severe, symptoms must not improve with standard measures and medications. Symptoms associated with severe asthma are similar to those of mild-to-moderate asthma; they are just more intense and can be life-threatening.