It’s a familiar nighttime frustration: you settle into bed, ready for restful sleep, only to be interrupted by a relentless cough. Coughing fits can disrupt your sleep and leave you feeling exhausted. But why does a cough often seem to intensify as soon as the lights go out? Understanding the reasons behind a cough that gets worse at night is the first step to finding relief and reclaiming your nighttime peace.
Coughing is a natural reflex that helps your body clear irritants and mucus from your airways. However, when coughing becomes persistent, especially at night, it signals an underlying issue. Experts suggest several reasons why your cough might be more bothersome when you’re trying to sleep.
The Science Behind Nighttime Coughs
One primary reason for increased nighttime coughing relates to mucus and postnasal drip. During the day, gravity and movement assist your body in draining mucus. As Vontrelle Roundtree, MD, associate chief medical officer at MDLIVE of Evernorth, explains, “Moving around during the day makes it easier for the body to loosen trapped mucus.” However, when you lie down, this process becomes less efficient. Mucus can pool in the back of your throat, triggering the cough reflex. This is known as postnasal drip, a common culprit behind nighttime coughing.
Furthermore, lying down impacts the function of cilia, the tiny hair-like structures in your lungs that work to remove mucus. According to Samuel Mathis, MD, assistant professor in the Department of Family Medicine at University of Texas Medical Branch, “with lung infections, lying down helps the cilia to more effectively move mucus out of the lungs, and the cough reflex is our body’s attempt to get rid of the excess mucus.” Essentially, while cilia might be more active in moving mucus when you are prone, the accumulated mucus can still stimulate more coughing as your body tries to expel it.
Sleep also plays a critical role in your immune response. Dr. Roundtree notes, “During sleep, the body regulates our production of cytokines… If you have a nagging cough that causes you to wake up often throughout the night, it compromises sleep quality, potentially affecting your body’s cytokine regulation and making it difficult for your immune system to combat and recover from sickness.” The disruption caused by nighttime coughing can hinder your body’s ability to heal and fight off infections that may be causing the cough in the first place.
Other Contributors to Nighttime Coughs
Beyond mucus and body position, other health conditions can exacerbate coughing at night. Gastroesophageal reflux disease (GERD), or acid reflux, is a significant factor. Sarah McBane, PharmD, associate dean of pharmacy education at the University of California, Irvine School of Pharmacy, points out that “The act of lying down can cause the reflux to get worse, and then, of course, you may cough more.” When stomach acid flows back into the esophagus, it can irritate the throat and trigger coughing, particularly when lying flat.
Conditions like asthma and allergies are also known to cause coughs that worsen at night. Asthma can cause airway inflammation and narrowing, leading to increased coughing, especially when lying down. Allergies can produce postnasal drip and airway irritation, both of which can intensify coughs during the night.
If you find yourself consistently battling a cough that gets worse at night, it’s important to consider the potential causes. Addressing issues like postnasal drip, managing acid reflux, and properly treating conditions like asthma and allergies can significantly improve your nighttime comfort and sleep quality. If your nighttime cough persists or is accompanied by other concerning symptoms, consulting a healthcare professional is recommended to determine the underlying cause and receive appropriate guidance.
