There are several reasons why asthma symptoms might be worse at night.
The triggers for your asthma may be primarily in the bedroom. These could include:
- Dust mites in the pillow, mattress, other bedding, or the rug
- Animals that either live or go in and out of the bedroom
Asthma sufferers are quite sensitive to changes in temperature and humidity. You need to find the right environment for you. People respond differently to air that is too hot, too cold, too moist or too dry.
Another possibility is that your controller medicine, such as an inhaled corticosteroid, is wearing off. This is more likely if you take the puffs only in the morning. You may need to use it twice per day, with a second dose before you get into bed.
Many people find that lying down makes them more uncomfortable, although the asthma itself isn't worse. Try propping yourself up rather than lying flat in bed.
Another cause for worse symptoms at night is gastroesophageal reflux (GERD). When lying flat, acid comes up the esophagus and into the back of the throat. Then, a small amount of acid can slide into the upper bronchial tubes and cause them to tighten. This could cause more wheezing.