Reviewed by: HU Medical Review Board | Last reviewed: October 2021
Nighttime or nocturnal asthma is a type of asthma where symptoms get worse at night. It is a very common type of asthma. About 75 percent of people with asthma get woken up by symptoms at least once a week. Nearly half of people with asthma experience symptoms every night.1,2
Nighttime asthma may cause you to wake up from symptoms. It may also make you tired during the day because of sleep disturbances. More sleep disturbances are a sign that your asthma is not controlled well. Talk to your doctor about adjusting your treatment plan to improve nighttime symptoms.
What are symptoms and complications of nighttime asthma?
Any other type of asthma can also be nighttime asthma. Nighttime asthma has similar symptoms to other types of asthma, including:3
- Shortness of breath
- Chest tightness
The key difference with nighttime asthma is that symptoms get worse at night. They may wake you up several times. Sleep disturbance can happen several times per week. This can cause you to get tired during the day.2
Waking up even a few nights every month from asthma symptoms can impact work and school performance. Nighttime asthma can cause other long-term effects. It can worsen lung function and asthma symptoms. It also increases the risk of heart disease and other health problems.2,4
What causes nighttime asthma?
Normal day/night body fluctuations contribute to nighttime asthma. Your body has an internal clock called a circadian rhythm. This clock regulates 24-hour cycles of body functions. Variations during this cycle impact lung function during sleep. Body changes during sleep that cause symptoms include:2
- Shallower breathing because of less muscle movement
- Narrower airways
- Higher inflammation and immune system activity
- Hormonal changes that affect your breathing
- Pauses in breathing during sleep
Sleeping in a room with asthma triggers can also cause nighttime asthma. For example, sleeping with the windows open may increase pollen exposure at night. Pets and fabrics can also worsen your asthma at night. Tobacco smoke, food allergens, and cold air can also trigger nighttime symptoms.2
Certain other health conditions increase the risk of nighttime asthma, including:2,5,6
- Gastroesophageal reflux disease (GERD)
- Obstructive sleep apnea (OSA)
How is nighttime asthma diagnosed?
Nighttime asthma is easy to diagnose if symptoms clearly get worse at night. In this case, your doctor may diagnose you with nighttime asthma in addition to other types of asthma.2,7
Nocturnal asthma often goes undetected in children because they may not report nighttime symptoms. Monitoring children’s nighttime symptoms can help diagnose nighttime asthma and prevent sleep disturbances.2,7
Certain diagnostic tests can also help identify nighttime asthma. Your doctor may have you use a spirometer or peak flow meter to measure lung function at home. You can do this before you go to sleep and after you wake up. This can help doctors see how lung function changes overnight.3
If symptoms are more severe, you may undergo a sleep study. This diagnostic test tracks many body measurements during sleep. A sleep study can also be helpful to diagnose sleep apnea. This is typically linked to loud snoring and gasping for air in the middle of the night. Inform your doctor if you have experienced these symptoms.3
How is nighttime asthma treated?
Treatment of nighttime asthma involves the same long-term management techniques as other types of asthma. Poorly controlled or severe asthma increases the risk of nighttime symptoms. Waking up from asthma symptoms more than 1 to 2 times per week is a sign that your asthma is not well-controlled. The goal is to reduce or eliminate nighttime symptoms.2
Long-term asthma control drugs are key to managing nighttime asthma. This can include inhaled corticosteroids, long-acting beta-agonists, and leukotrienes. Using them at the proper time of day is important. Talk to your doctor about when to take medicines to control nighttime symptoms.2
Lifestyle changes and other treatments may also improve nighttime symptoms, such as:2,8
- Following a regular sleep schedule
- Avoiding stressful activities before bed
- Reducing exposure to environmental triggers during sleep, like dust mites and pet dander
- Closing windows to avoid temperature changes, pollen, and air pollution in the bedroom
- Aerobic exercise
- Managing any other health problems, especially breathing problems