Some key factors that contribute to nighttime asthma attacks include:

Your body’s internal clock. Your circadian rhythm causes some of your hormone levels to fall at night. Lower levels of hormones can cause your airways to narrow slightly. These narrowed airways can exacerbate your asthma symptoms, according to the Asthma Society of Canada (ASC).

Dust mites. Your pillows, blankets, and mattress can all be a haven for these microscopic insect-like pests and their waste. Allergies to dust mites can worsen asthma, and you could be wallowing in them as you sleep, according to the ASC.

Gravity. When you lie down, your chest and lungs naturally experience extra pressure, the ASC says.

If you have trouble sleeping due to severe asthma, be sure to talk with your doctor, Dr. Bose says. “It’s important to share your nighttime symptoms with your doctor because it’s one of the ways he or she can determine how well your asthma is controlled," she says. “People with asthma tend to underreport their nighttime symptoms, which can be a sign that you need more of your medication or a change in treatment.” Your doctor may need to make adjustments to your asthma treatment plan so you feel better, day and night, Bose says.

How to Sleep Better With Severe Asthma

In addition to taking asthma medications as prescribed, here are seven steps you can take to lower your chances of having a nighttime asthma attack:

  1. Clean your bedroom regularly. Use a vacuum with a high-efficiency particulate air (HEPA) filter to trap mites and their waste and get them out of your bedroom. If your vacuum doesn’t have a HEPA filter, you can buy one from an allergy supply company, according to the Asthma and Allergy Foundation of American (AAFA).
  2. Wash your bedding in hot water weekly. Make sure the water is at least 130 degrees Fahrenheit so it will kill dust mites. Finish the job in a hot dryer.
  3. Invest in dust-proof mattress and pillow protectors. These zippered covers are woven tightly to keep dust mites out of bedding. You can find them at bedding and housewares stores, the AAFA says.
  4. Invest in a humidifier. Cold air is drier and more troublesome for people with severe asthma. Depending on where you live, you might benefit from a humidifier to add moisture to the air in your bedroom in the winter, Bose says. What’s more: Dust mites thrive in low humidity, so boosting humidity by using a humidifier in your bedroom can help keep dust mites at bay.
  5. Don’t sleep with pets. “If you have pets, keep them out of the bedroom so their dander doesn’t collect or stick to the carpeting and bedding,” Bose says. You may also need to keep the door to your bedroom shut to keep your pet — and its dander — out.
  6. Keep your head up. If you have a cold or a sinus infection, lying flat can exacerbate postnasal drip, which can trigger an asthma attack, Bose says. Also, if you have acid reflux, lying flat can allow more acid to creep up into your throat, she says. When you sleep, keep your head slightly elevated, the AAFA suggests.
  7. Get tested for sleep apnea. People with asthma may be at increased risk for sleep apnea, according to the American Thoracic Society. Sleep apnea causes repeated breaks in your breathing while you sleep. It can also worsen asthma symptoms. Talk with your doctor about testing and treatment if necessary. By taking these steps to create a sleeping environment free of asthma triggers, you should find it easier to prevent nighttime asthma attacks and get better sleep.