It’s undeniably frustrating to deal with a cough, but it becomes especially bothersome when that cough intensifies or occurs more frequently at night. This nighttime coughing can significantly disrupt your relaxation, sleep onset, sleep quality, and the restorative rest your body needs, particularly when you’re trying to recover from an illness.
According to Dr. Vontrelle Roundtree, Associate Chief Medical Officer at MDLIVE of Evernorth, sleep is crucial for immune function. “During sleep, the body regulates our production of cytokines, signaling proteins our immune systems produce to fight off invading pathogens such as viruses and bacteria,” she explains. “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.” Therefore, understanding why coughs worsen at night is not just about comfort, it’s also about supporting your body’s natural healing processes.
Beyond hindering recovery, nighttime coughing can trigger additional symptoms that further impede restful sleep. Dr. Roundtree notes, “Coughing may also cause dry throat and mouth, postnasal drip, and physical discomfort that makes for a less-than-peaceful sleep experience.” These accompanying issues can amplify the disruption caused by the cough itself, creating a cycle of discomfort and sleeplessness.
The Science Behind Nighttime Coughs
There are several reasons why coughing can feel and actually become worse when you lie down for the night. Many of these reasons are linked to how our lungs and airways function, especially in different body positions. Conditions such as infections, postnasal drip, allergies, and asthma are known culprits behind coughs that intensify at night, as highlighted by Dr. Samuel Mathis, Assistant Professor in the Department of Family Medicine at the University of Texas Medical Branch.
Dr. Mathis elaborates on lung infections, stating, “with lung infections, lying down helps the cilia [little ‘hairs’ in our lungs] 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.” During the day and when upright, gravity assists in draining mucus, but when you lie down, this process changes. The change in body position means mucus can pool, stimulating the cough reflex.
Dr. Roundtree further explains the role of body position and mucus: “Moving around during the day makes it easier for the body to loosen trapped mucus. When we lie down to rest at night, this position can make it more challenging for our bodies to naturally clear this mucus, resulting in what we call postnasal drip — nasal secretions that pool in the back of the throat and cause those pesky coughs.” This pooling of secretions in the throat area when lying down is a primary reason why you might find yourself coughing more frequently once you’re in bed.
Other Contributing Factors to Night Coughs
Besides mucus and lung-related issues, nighttime coughs can also be a symptom of gastroesophageal reflux disease (GERD), commonly known as acid reflux. “GERD happens when stomach acid flows back into the esophagus, irritating its lining and potentially reaching the back of your throat,” explains Dr. Roundtree. This backflow of stomach acid is often exacerbated by lying down.
Dr. Sarah McBane, Associate Dean of Pharmacy Education at the University of California, Irvine School of Pharmacy, adds to this, “The act of lying down can cause the reflux to get worse, and then, of course, you may cough more.” When you are upright, gravity helps keep stomach acid down. However, in a horizontal position, it’s easier for stomach acid to travel up into the esophagus and even reach the throat, triggering cough reflexes as the body tries to clear the irritant.
Understanding these various factors, from mucus drainage and lung function to acid reflux, can help in managing and addressing why coughs get worse at night. Recognizing the cause is the first step towards finding effective relief and ensuring a more restful night’s sleep.
