What Is Seasonal Affective Disorder? Seasonal affective disorder (SAD) is depression that happens only at a specific time of year. With SAD, a person becomes depressed in fall or winter, when days are ...

What Are My Baby’s Weight and Size at 11 Weeks? Your baby at 11 weeks is about the size of a golf ball or ping-pong ball, which is just over 1 ½ inches. Your baby weighs about 1.6 ounces (45.93 grams) ...

What Are the Lungs and Respiratory System? The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out ...

Medically reviewed by: Larissa Hirsch, MDThis link opens in a new tab Learn About Primary Care Pediatrics at Nemours Children's HealthThis link opens in a new tab When we breathe, the respiratory ...

Medically reviewed by: KidsHealth Medical ExpertsThis link opens in a new tab Learn About Primary Care Pediatrics at Nemours Children's HealthThis link opens in a new tab Every single person has a ...

Medically reviewed by: T. Ernesto Figueroa, MDThis link opens in a new tab Learn About Urology at Nemours Children's HealthThis link opens in a new tab Testicular torsion is an emergency condition. It ...

Medically reviewed by: Lonna P. Gordon, MDThis link opens in a new tab Learn About Adolescent Medicine & Pediatric Gynecology at Nemours Children's HealthThis link opens in a new tab To help protect ...

Your eyes see, but how does vision happen? Find out how the eyes and brain work together in this eye video.

Medically reviewed by: Amy W. Anzilotti, MDThis link opens in a new tab Learn About Primary Care Pediatrics at Nemours Children's HealthThis link opens in a new tab A breath holding spell is when a ...

Medically reviewed by: Patrick C. Barth, MDThis link opens in a new tab Learn About Otolaryngology (Ear, Nose, & Throat Care) at Nemours Children's HealthThis link opens in a new tab A perforated ...

Medically reviewed by: KidsHealth Medical ExpertsThis link opens in a new tab Learn About Primary Care Pediatrics at Nemours Children's HealthThis link opens in a new tab Reproduction is the process ...

Medically reviewed by: Yamini Durani, MDThis link opens in a new tab Learn About Primary Care Pediatrics at Nemours Children's HealthThis link opens in a new tab ...