Bronchiolitis often starts with a runny or blocked nose and a cough, much like a common cold. It mostly affects children under age 2. Over the next few days, the cough may become more noticeable, and breathing may become faster or noisier, sometimes with wheezing. Some children develop a mild fever or feed less than usual. Breathing difficulty, pauses in breathing, or blue or grey lips need urgent medical attention.
How do a runny nose and cough relate to bronchiolitis?
Bronchiolitis is a viral infection that causes swelling and mucus buildup in the smallest airways of the lungs, called bronchioles. It commonly affects infants and young children, particularly during their first two years of life. The respiratory syncytial virus (RSV) is a frequent cause, although other respiratory viruses can also lead to the infection.
According to Mayo Clinic, bronchiolitis usually begins with cold-like symptoms, including a runny nose, nasal congestion and a cough. These early symptoms may appear before signs of lower airway involvement, such as wheezing or difficulty breathing.
What are the early symptoms of bronchiolitis?
At first, the symptoms may look much like those of an ordinary cold. A child may seem generally well but develop nasal discharge, congestion or a mild cough. Other symptoms can appear as the infection progresses. Examples include:
- Runny nose: Clear nasal discharge may be one of the first noticeable symptoms.
- Blocked nose: Congestion may make it harder for a baby to breathe comfortably through the nose, especially during feeding.
- Cough: The cough may begin mildly and become more frequent or persistent over the following days.
- Mild fever: Some children develop a slightly raised temperature, although fever does not occur in every case.
- Irritability: A baby may become unsettled, fussier than usual or less interested in feeding.
According to the NHS, early bronchiolitis symptoms commonly resemble a cold, with sneezing, a runny or blocked nose and a slightly high temperature. A cough, faster breathing and noisy breathing may follow. A runny nose and cough can also occur with other respiratory infections, so these symptoms alone cannot establish the cause.
How do symptoms change as bronchiolitis develops?
Bronchiolitis may begin with mild nasal symptoms before the cough and breathing symptoms become more noticeable. As swelling and mucus affect the small airways, some children develop wheezing, faster breathing or difficulty feeding. These changes do not occur in the same way in every child, and some infants have relatively subtle early symptoms.
MedlinePlus describes bronchiolitis as an illness that can start as a mild upper respiratory infection and progress over the next few days to more noticeable coughing, wheezing and breathing difficulties. The pattern over time can help a healthcare professional assess what is happening, particularly when considered alongside the child's age, medical history and physical examination.
What does a bronchiolitis cough sound like?
The cough may be dry or sound as though mucus is present. It can become more frequent as the illness progresses. Some children also develop wheezing, a high-pitched whistling sound that is usually heard when breathing out. Other signs of breathing difficulty include grunting, flaring nostrils or skin pulling inward around the ribs during inhalation.
Not every child with bronchiolitis has all these symptoms. A cough that sounds wet, dry or unusually frequent is not enough on its own to identify the infection. The child's breathing pattern, feeding, alertness and overall condition are also important.
How long do a runny nose and cough last?
The course of bronchiolitis varies. Nasal symptoms often appear first, while coughing and breathing symptoms may become more noticeable over the next several days. According to the NHS, symptoms are commonly at their worst between days three and five, and the cough usually improves within about three weeks.
Some children recover sooner, while others may cough for longer. Improvement should be judged by the child's overall condition as well as the cough itself. If symptoms continue to worsen, feeding becomes difficult, breathing changes or recovery does not seem to be progressing, seek medical advice rather than relying on the expected timeline alone.
When should you seek medical help?
A runny nose and cough do not always require emergency care, but changes in breathing or feeding can signal a more serious illness. Infants younger than three months, babies born prematurely and children with certain heart, lung or immune conditions may need particular attention when respiratory symptoms develop.
Get emergency medical help if a child:
- Is struggling to breathe, grunting with each breath or showing marked pulling in of the skin around or beneath the ribs.
- Has pauses in breathing.
- Develops blue or grey lips, tongue or skin.
- Becomes unusually floppy, very weak or difficult to wake.
- Is too breathless to feed or drink.
These signs need immediate assessment. Cleveland Clinic also advises urgent medical attention for children with bronchiolitis symptoms who develop difficulty breathing or other signs of serious illness. Contact your local emergency service if a child is having severe breathing problems.
Contact a healthcare professional promptly if:
- The cough or cold symptoms are getting worse rather than improving.
- Your baby is feeding substantially less than usual or has noticeably fewer wet nappies or diapers.
- Your child shows signs of dehydration, such as a very dry mouth or unusually little urine.
- Your baby is younger than three months and has a temperature of 38°C (100.4°F) or higher.
- Your child seems unusually tired, irritable or different from their normal self.
If a baby has a runny nose and cough but is breathing comfortably and feeding normally, continue to observe the child's overall condition. Arrange a medical assessment if you are concerned, particularly if the baby is very young or has an underlying health condition.
How can you tell whether symptoms need closer attention?
Pay attention to more than the presence or frequency of a cough. Notice whether the child is breathing comfortably at rest, feeding close to their usual amount, producing wet nappies or diapers and responding normally. Changes across these everyday activities can provide useful information when describing symptoms to a healthcare professional.
According to Mayo Clinic Health System, bronchiolitis can cause nasal discharge, congestion, coughing and sometimes wheezing in young children. A clinician can assess the child's symptoms, their progression and examination findings to decide whether further evaluation or supportive care is needed.
When discussing symptoms with a healthcare professional, note when the runny nose and cough began, whether breathing has changed, whether a fever has occurred and how much the child is drinking or feeding. These details can help the clinician understand the pattern of illness and determine the appropriate next steps.