Most babies and older children have several mild infections of the respiratory system each year.

Upper respiratory system

The upper respiratory system includes the nose, ears, sinuses, and throat. A child with an upper respiratory infection may feel uncomfortable and sound very congested. Other symptoms of an upper respiratory infection include:

• A runny or stuffy nose. This may lead to blockage of the nasal passages, causing the child to breathe through his or her mouth.
• Irritability, restlessness, poor appetite, and decreased activity level.
• Coughing, especially when lying down.
• Fever that occurs suddenly and may reach 105F.

Lower respiratory system

The lower respiratory system includes the bronchial tubes and lungs. Respiratory problems are less common in the lower respiratory system than in the upper respiratory system.

Symptoms of a lower respiratory (bronchial tubes and lungs) problem usually are more severe than symptoms of an upper respiratory (ears, nose, sinuses, and throat) problem. A child with a lower respiratory problem is more likely to require a visit to a doctor than a child with an upper respiratory problem.

Symptoms of lower respiratory system infections include:

• Shallow coughing, which continues throughout the day and night.
• Fever, which may be high with some lower respiratory system infections, such as pneumonia.
• Difficulty breathing. You may notice:
  • Rapid breathing.
  • Grunting, which is heard during the breathing out (exhaling) phase of breathing. Most babies grunt occasionally when they sleep. But grunting that occurs with rapid, shallow breathing may indicate lower respiratory system infection.
  • Wheezing (which is a different sound than croup).
  • Flaring the nostrils and using the neck, chest, and abdominal muscles to breathe, causing a "sucking in" between or under the ribs (retractions).

Respiratory problems may have many causes.

Viral infections

Viral infections cause most upper respiratory infections. Sore throats, colds, croup, and influenza (flu) are common viral illnesses in babies and older children. These infections are usually mild and go away in 4 to 10 days, but they can sometimes be severe. For more information, see the topics Croup or Influenza.

Home treatment can help relieve the child's symptoms. The infection usually improves on its own within a week and is gone within 14 days.

Antibiotics are not used to treat viral illnesses and do not alter the course of viral infections. Unnecessary use of an antibiotic exposes your child to the risks of an allergic reaction and antibiotic side effects, such as nausea, vomiting, diarrhea, rashes, and yeast infections. Antibiotics also may kill beneficial bacteria and encourage the development of dangerous antibiotic-resistant bacteria.

Viral lower respiratory system infections may be mild, similar to upper respiratory system infections. An example of a possibly serious viral infection is bronchiolitis. Up to 10% of babies and children with viral infections of the lower respiratory system, such as those caused by respiratory syncytial virus (RSV), may develop severe blockage of the air passages and require hospitalization for treatment. For more information, see the topics Acute Bronchitis and Pneumonia.