Shortness of breath, wheezing, and coughing are annoying enough during the day. Waking up in the middle of a coughing fit or being unable to catch your breath in the quiet of the night is downright disturbing. Unfortunately, approximately 30 to 70% of people with asthma experience nocturnal asthma, or a worsening of asthma symptoms at night. Not everyone with asthma feels worse at night, but many do.
Learn more about nocturnal asthma and what to do if you have nighttime asthma with cough and other symptoms.
The most common reasons asthma is worse at night:
Exposure to allergens. Bedbugs. Pet dander. Dust mites. All are common in the bedroom, and all can trigger asthma attacks. You probably spend 6 to 9 hours in bed every day; that’s a long time to be exposed to potential allergens. Some people also experience delayed allergic reactions at night. It’s not uncommon for an allergic response to occur 3 to 8 hours after exposure to an allergen. If you’re exposed to pollen, for instance, in the early evening, you might experience shortness of breath and wheezing when you’re trying to fall asleep.
Supine position and acid reflux. When we lie down, it’s easier for stomach acid to travel back up into the esophagus, the tube connecting the mouth and stomach.Instead of being swallowed, some of this fluid can enter the large airways and provoke an irritating cough. Reflux of stomach acid can also cause the airways to constrict, which leads to more difficulty breathing.
Postnasal drip. People are more susceptible to postnasal drip at night. When you lie flat, it’s easier for fluid to drip down the back of your throat and cause coughing. Lying down also causes fluid to shift from the legs to the chest, which can lead to increased fluid accumulation in the airway walls and narrowing of the breathing passages.
Circadian changes in lung function. Our lungs work differently during the night. Perhaps because human beings evolved to be active during the day, our lung function is best during the day. Airway resistance increases throughout the night, and that effect is more pronounced in people with asthma.
Stress. At least one study has found a relationship between stress and nighttime asthma. Hormones released by the body in times of stress can cause inflammation, so researchers theorize that stress may lead to narrowed airways, at least in some people.
If you wake up in the middle of an asthma attack, use your rescue inhaler. (It’s a good idea to keep it within reach of your bed, especially if you’re prone to nocturnal asthma.) Adopting a more upright position may help too. Some people find that a drink of water can ease a cough.
If you regularly experience asthma symptoms at night, talk with your healthcare provider about the problem. Adjusting the timing of your asthma medicine may help. Some studies, for instance, have shown that an 800 microgram dose of inhaled triamcinolone (Azmacort) at 3 pm is more effective than taking 200 micrograms of it four times a day.
Your healthcare provider may also need to increase or add medication. Asthma tends to get worse over time, and if you’re having symptoms at night, your asthma may be poorly controlled. Tweaking your asthma management plan may eliminate your nighttime symptoms.
Exercise can help alleviate nocturnal asthma as well. Studies have found that physical activity at least twice a week for 6 to 8 weeks decreased nighttime asthma symptoms in children. Ten to 12 weeks of physical exercise also decreased nocturnal asthma and improved sleep in adults.
People whose asthma is worse at night should see a healthcare provider and ask about nocturnal asthma treatment.