It is more common in children aged 3 months to 6 years because their trachea is small at this age; there is therefore a greater risk of swelling. The infection causes swelling and numerous secretions in the larynx, trachea and bronchioles of the lungs. As a result, difficulty breathing occurs and a deep, dry cough begins. Imaging is not essential for diagnosing croup, however, radiologists will take anterior and lateral x-rays of the neck. This is used to rule out other diseases such as foreign bodies, abscesses, epiglottitis and other possibilities. In some cases where croup is recurring, patients may need a bronchoscopy or endoscopy to determine why it is recurring. (Desai) Croup is normally diagnosed based on clinical assessments. Respiratory therapists will examine “respiratory status and rate, retraction, stridor, heart rate, and sometimes pulse oximetry to test the severity of the disease.” (Zoorob) Most treatments are self-care, but in some cases a respiratory therapist is needed to perform them. They can administer oxygen when the patient is hypoxic. They may also use humidification therapy, which helps break up secretions caused by croup and make them thinner. They may also administer nebulized epinephrine. In extreme cases, a breathing tube may be necessary.