A sore throat often worsens at night. This phenomenon can be attributed to several physiological and environmental factors that affect the throat during sleep. Understanding these reasons can help manage the discomfort.
Positional and Gravity Effects
Lying down alters how mucus drains from the nasal passages and throat. During the day, gravity helps clear these substances. However, when horizontal, mucus from the sinuses can accumulate and drip down the back of the throat, known as post-nasal drip. This excess mucus irritates the throat lining, leading to increased soreness. The pooling of mucus makes it more challenging for the body to clear, contributing to irritation.
Post-nasal drip can trigger a cough that further exacerbates throat pain. Elevating the head during sleep can help mitigate this by allowing gravity to continue assisting drainage.
Environmental Contributions
External factors in the sleeping environment contribute to a sore throat worsening at night. Dry air, often from heating or air conditioning systems, can dehydrate the throat’s mucous membranes. This dryness makes the throat more susceptible to irritation. Sleeping with an open mouth in a dry environment can intensify this effect.
Bedrooms can harbor allergens like dust mites and pet dander. Prolonged exposure to these irritants during sleep can trigger or exacerbate throat irritation, especially for those with allergies. These allergens can increase mucus production, contributing to nighttime throat discomfort. Using a humidifier and regularly cleaning the bedroom can help reduce these environmental impacts.
Reduced Saliva Production and Swallowing
During sleep, the body reduces saliva production, leading to a drier throat environment. Saliva plays a role in lubricating the throat and washing away irritants and bacteria. With less saliva, the throat’s protective mechanisms are diminished, making it more vulnerable to discomfort.
The frequency of swallowing decreases during sleep compared to waking hours. While awake, people typically swallow about once every minute; this drops to approximately once every 5-10 minutes in deeper sleep stages. This reduced swallowing means irritants and accumulated mucus remain in contact with throat tissues for longer, intensifying soreness. The combination of decreased saliva and infrequent swallowing can leave the throat feeling parched and irritated upon waking.
Acid Reflux
Stomach acid can reflux into the esophagus and throat, particularly when lying flat. This phenomenon, known as acid reflux or gastroesophageal reflux disease (GERD), occurs more easily at night because gravity no longer helps keep stomach contents in place. The lower esophageal sphincter, a muscle that typically prevents acid from flowing upward, may relax, allowing acid to escape. This acid can irritate the tissues of the throat and voice box, leading to a burning sensation or a raw, sore throat that is often worse upon waking.
Acid reflux can also manifest as laryngopharyngeal reflux (LPR), where stomach contents reach the throat and voice box without causing traditional heartburn symptoms. Common triggers include eating large or fatty meals, consuming certain foods like chocolate, coffee, or alcohol, and lying down too soon after eating. Elevating the head of the bed and avoiding late-night meals can help manage these symptoms.