Diagnosis

Tests and X-rays are not usually needed to diagnose bronchiolitis. The doctor can usually identify the problem by observing your child and listening to the lungs with a stethoscope.

If your child is at risk of severe bronchiolitis, if symptoms are worsening or if another problem is suspected, your doctor may order tests, including:

• Chest X-ray. Your doctor may request a chest X-ray to look for signs of pneumonia.
• Viral testing. Your doctor may collect a sample of mucus from your child to test for the virus causing bronchiolitis. This is done using a swab that's gently inserted into the nose.
• Blood tests. Occasionally, blood tests might be used to check your child's white blood cell count. An increase in white blood cells is usually a sign that the body is fighting an infection. A blood test can also determine whether the level of oxygen has decreased in your child's bloodstream.

Your doctor may also ask you about signs of dehydration, especially if your child has been refusing to drink or eat or has been vomiting. Signs of dehydration include sunken eyes, dry mouth and skin, sluggishness, and little or no urination.