Asthma is often put into categories or groups based on the "triggers" that cause the asthma symptoms or attacks. These categories or types of asthma are: 

Allergic asthma

Allergic asthma is triggered by an allergic reaction to allergens such as pollens or pet dander. People with this type of asthma typically have a personal and/or family history of allergies (such as hay fever) and/or eczema (skin problem resulting in itching, a red rash, and sometimes small blisters). 

Seasonal asthma

Seasonal asthma, a form of allergic asthma, can be triggered by trees, grasses, or flowers releasing pollen into the air. For example, some people find that their asthma is worse in the spring when there is an increase in flowering plants. Others find their asthma is worse in the late summer or early fall when ragweed and mold from leaves on trees are more likely to cause problems. 

Non-allergic asthma

For some people with asthma, asthma attacks have nothing to do with allergies. Although these people get the same symptoms and have similar changes in their airways as patients with allergic asthma, their asthma is not triggered by allergies. However, like any patient with asthma, asthma attacks may be triggered or made worse by one or more nonallergic asthma triggers including materials (irritants) in the air you breathe, such as tobacco smoke, wood smoke, room deodorizers, pine odors, fresh paint, household cleaning products, cooking odors, workplace chemicals, perfumes, and outdoor air pollution. Respiratory infections, such as the common cold, the flu, or a sinus infection may also give you symptoms. Finally, exercise, cold air, sudden changes in air temperature, and even gastroesophageal reflux (heartburn) may be triggers for people with non-allergic asthma. 

Exercise-induced asthma

Exercise-induced asthma (EIA) simply refers to asthma symptoms that are triggered by exercise or physical activity. These symptoms are usually noticed during or shortly after exercise. Exercising outdoors in the winter seems to be particularly bad for patients with this type of asthma. 

Nocturnal asthma

Can occur in a patient with any type of asthma. It refers to asthma symptoms that seem worse in the middle of the night, typically between 2 and 4 AM. 

Things that can cause asthma symptoms to get worse at night may include sinus infections or postnasal drip caused by allergens like dust mites or pet dander. Your body clock may also play some role: levels of substances your body makes like adrenaline and steroids, both of which protect against asthma, are lowest between 4 and 8 AM, making it easier for people with asthma to get symptoms during these times.