The American Academy of Otolaryngology—Head and Neck Surgery (AAO-HNS) is the world's largest organization of physicians dedicated to the care of ear, nose, and throat (ENT) disorders. Its Web site includes information for the general public on ENT disorders.

The Centers for Disease Control and Prevention (CDC) is an agency of the U.S. Department of Health and Human Services. The CDC works with state and local health officials and the public to achieve better health for all people. The CDC creates the expertise, information, and tools that people and communities need to protect their health—by promoting health, preventing disease, injury, and disability, and being prepared for new health threats.

This Web site is sponsored by Nemours Foundation. It has a wide range of information about children's health, from allergies and diseases to normal growth and development (birth to adolescence). This Web site offers separate areas for kids, teens, and parents, each providing age-appropriate information that the child or parent can understand. You can sign up to get weekly e-mails about your area of interest.

The National Institute of Allergy and Infectious Diseases conducts research and provides consumer information on infectious and immune-system-related diseases.