An otolaryngologist – a head and neck surgeon - provides comprehensive medical and surgical care for adult and pediatric patients with diseases and disorders that affect the ears, nose and throat (ENT), the respiratory and upper alimentary systems, and related structures of the head and neck. Many otolaryngologists focus on one or more subspecialty areas, including: allergy; facial plastic and reconstructive surgery; head and neck surgery (benign and malignant tumors including the thyroid and parathyroid glands); laryngology (voice and swallowing disorders); otology/audiology; and rhinology (nose and sinus disorders). In addition, otolaryngologists can be sub-certified by taking additional training and an examination in disorders of the inner ear and sleep medicine.