At the end of a long day, you're tired. All you want to do is let your head hit that pillow so you can drift off into a restful and deep sleep. But, no luck. Like clockwork, you're unable to cash in on optimal REM because of a persistent nighttime cough. And if you're one of the estimated 27 million people in the world with asthma, you might not be just dealing with a cough; it might actually be nocturnal asthma at play, which can seriously mess with your sleep.
Nocturnal asthma is exactly what it sounds like—an exacerbation of asthma that occurs during nighttime. Just as there is exercise- and allergy-induced asthma, nocturnal asthma is one specific form of the general condition, characterized by nighttime airway constriction that can lead to sleep disturbances. Research has found that among people with asthma, approximately 75 percent experience nocturnal asthma symptoms at least once a week, and 40 percent experience nightly symptoms. In plainer terms, a whole bunch of people are not sleeping well at least once a week because of nocturnal asthma.
The real number of people who deal with nocturnal asthma might even be much higher, due to underreporting of symptoms, according to research. Allergist Linda Cox, MD, says it's common for patients to mistake nocturnal asthma for something else altogether. "The symptom is typically coughing and being woken from sleep," she says, while "many asthmatics are used to being triggered by allergens and exercise."
If you have no idea you have nocturnal asthma, you probably wouldn't address it. Instead, you're likely to pay attention to the symptoms you are aware of. So, if a cough keeps you from sleeping, it would only make sense to treat it with cough medicine and then call it a night, right? Wrong. "It'd be like treating pain with some pain medicine, but if the pain is due to a serious medical problem, like an ulcer, just taking pain medicine is not the answer," says William Berger, MD, medical director and allergist with Allergy & Asthma Network.
With nocturnal asthma, your best bet for preserving a future of sleeping well and managing your symptoms comes with understanding your triggers and then treating the underlying issue. "There can be a variety of causes," says Leonard Bielory, MD, professor of medicine, allergy, and immunology at Hackensack College of Medicine.
What's behind your nocturnal asthma—and how to deal
Just like your sleep-wake cycle, your hormones follow a circadian rhythm, which can, in turn, impact your nocturnal asthma symptoms, particularly with regard to epinephrine and cortisol.
"Cortisol is a steroid with which we treat asthma," says Dr. Bielory. "Your body produces from the adrenal glands, and it has its highs and lows. It's not constantly at a single level, but it peaks and decreases." Its lowest level is around midnight when you might be trying to sleep, which may be connected to nocturnal airway obstruction.
It's similar to epinephrine, a hormone connected to your body's natural fight-or-flight response. "You normally produce epinephrine, and it relaxes the muscles in the airways," says Dr. Berger. "It also suppresses histamine, which is the chemical that causes a lot of mucus secretion and bronchospasm." Histamine is also connected to airway obstruction. (Your mind might conjure the familiar word antihistamines, which block the effects of histamine and are common for treating allergy and asthma symptoms.) "So epinephrine levels are very, very low during the night and histamine levels at highest," he adds.
While these spikes and dips of hormone levels are natural processes, Dr. Cox says seeking medical attention is important if they contribute to nocturnal asthma episodes. "Different approaches include having the patient monitor their lung functions with a peak flow meter—they would get a reading first thing in the morning and later in the afternoon," she says. "Their physician will review and make recommendations." Such recommendations might include medications like antihistamines.
Whenever you have a cold, it's harder to breathe when you're lying down. This is partly because of the mucus and post-nasal drip that can accompany common viruses. Those two symptoms are also hallmarks of nocturnal asthma. "When you recline, you have increased blood flow to your lungs, which causes more congestion, and the volume of your lungs decreases," says Dr. Berger. "That can lead to an increase in the airway resistance."
And if you have reflux, lying down isn't doing your body any favors, either. "The reflux of stomach acid up through the esophagus to the larynx may stimulate a bronchial spasm," says Dr. Cox.
Dr. Berger says common ways to treat reflux include medications like proton pump inhibitors, which help reduce stomach acid production (Prilosec and Prevacid are common brands). H2 blockers (a form of antihistamine) like Pepcid are another common treatment route for reducing stomach acid.
Hormones and sleeping position aside, if you're sensitive to dust mites or pet dander and those allergens in your bedroom, they may trigger a nocturnal asthma response. "You're exposing yourself to inhaling certain allergens in the bedroom, and that would be a true allergic response," says Dr. Bielory.
The best way to ease sleep-environment symptoms is to address the triggers. "If you've been outdoors, take your clothes off and jump in the shower because there's pollen on your body, and also, there can be pollen in your hair," says Dr. Berger.
He also recommends getting allergen-proof protectors for your pillows, mattress, and box spring—and to stay up-to-date on cleaning schedules. "As far as the linens, wash them at least once a week in hot water—at least 130°F," Dr. Berger says. "You don't want cold water—you want to kill allergens." Finish off by putting everything in the dryer for at least 15 minutes on a hot cycle.
Most importantly, if you are experiencing a chronic cough at night, seek medical care so you can troubleshoot the immediate symptoms and underlying issues most effectively. "Cough is a symptom; it's not a disease, and it can be due to one or many different things," says Dr. Berger. "If you have a chronic cough, you should see an allergist or a pulmonologist who can then do the proper testing, make the proper diagnosis, and treat you."