Why do cold symptoms worsen at night?

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Last updated: June 23, 2025View editorial policy

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From the Guidelines

Cold symptoms often worsen at night due to several physiological factors, including the accumulation of mucus in the throat and nasal passages, decreased production of stress hormones like cortisol, and the natural drop in body temperature. When you lie down, mucus can accumulate in your throat and nasal passages rather than draining naturally, causing increased congestion and coughing. Your body also produces fewer stress hormones like cortisol at night, which normally help suppress inflammation during the day. Additionally, your body temperature naturally drops in the evening as part of your circadian rhythm, which can make you more aware of fever symptoms. The bedroom environment may also contribute, as allergens like dust mites in pillows and bedding can aggravate respiratory symptoms. To manage nighttime symptoms, try elevating your head with extra pillows to improve drainage, using a humidifier to moisten dry air, taking appropriate over-the-counter medications like acetaminophen or ibuprofen before bed, and staying hydrated throughout the day. Antihistamines such as diphenhydramine (Benadryl) at a dose of 25-50mg can help with congestion and may promote sleep, while nighttime cold formulas containing dextromethorphan can reduce coughing, as suggested by studies 1. These approaches address the underlying physiological changes that make cold symptoms feel worse when you're trying to sleep. Some studies also suggest that symptomatic therapy is recommended for management of common cold symptoms, although antihistamines have more adverse effects than benefits when used alone, 1 out of 4 patients treated with combination antihistamine–analgesic–decongestant products has significant symptom relief 1. It's essential to note that antibiotics should not be prescribed for patients with the common cold, as they are not effective and lead to significantly increased risk for adverse effects 1.

From the Research

Cold Symptoms Worsening at Night

  • Cold symptoms can worsen at night due to various factors, including the body's natural circadian rhythm 2.
  • Research has shown that nasal secretion, a common symptom of colds, is greatest in the morning, decreases over the day, and then slightly increases in the late evening 2.
  • This diurnal variation in symptom severity can make cold symptoms feel worse at night.
  • Additionally, the body's temperature rhythm can also play a role, with some illnesses like influenza B producing an increase in temperature and drowsiness, which can worsen at night 2.

Circadian Rhythm and Symptom Severity

  • The circadian rhythm, regulated by the suprachiasmatic nucleus (SCN) in the brain, can influence the severity of symptoms, including those of colds and influenza 2, 3, 4.
  • The production of melatonin, a hormone that regulates sleep-wake cycles, can also affect symptom severity, with levels typically increasing at night 4.
  • Disruptions to the circadian rhythm, such as those experienced by individuals with restless legs syndrome, can worsen symptoms at night 3.

Treatment and Management

  • While there is no direct evidence on treating cold symptoms that worsen at night, research suggests that managing the underlying circadian rhythm and sleep-wake cycle can help alleviate symptoms 4.
  • Techniques such as bright light exposure, melatonin supplementation, and physical exercise can help regulate the circadian rhythm and improve sleep quality 4.
  • However, it is essential to consult with a healthcare professional before attempting any new treatments or therapies.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diurnal variation in the symptoms of colds and influenza.

Chronobiology international, 1988

Research

Circadian rhythm of periodic limb movements and sensory symptoms of restless legs syndrome.

Movement disorders : official journal of the Movement Disorder Society, 1999

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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