Symptoms can range from mild to severe and may include:

• Breathing noises that may change with position and improve during sleep
• Breathing problems that get worse with coughing, crying, feeding, or upper respiratory infections
• High-pitched breathing
• Rattling or noisy breaths

A physical examination confirms the symptoms. An x-ray will be done to rule out other problems. The chest x-ray may show narrowing of the trachea when breathing in.

A procedure called a larngoscopy provides a definitive diagnosis. This procedure lets the otolaryngologist (ear, nose, and throat doctor, or ENT) see the airway structure and determine the severity of the problem.

Other tests that may be done include:

• Airway fluoroscopy
• Barium swallow
• Bronchoscopy -- camera down the throat to see the airways and lungs
• CT scan
• Lung function tests
• Magnetic resonance imaging (MRI)