Health Library A to Z
Light enters the eye through the cornea and passes through the pupil. It then hits the lens. This focuses the light rays on the retina. The optic nerve carries the image from the retina to the brain.
Problems with Vision
Eye disorders in children are either refractive or nonrefractive errors. Refractive errors are those caused by the shape of the eye. Nonrefractive errors are caused by disease.
Tympanostomy (ear) tubes are small tubes. They’re placed into your child’s eardrum by an ear, nose, and throat (ENT) surgeon. The tubes may be made of plastic, metal, or other material.
Vaginitis in Adolescents
Vaginitis is a common problem for women of all ages. Bacteria, yeast, viruses, and chemicals in creams or sprays can cause it.
Vaping and E-Cigarettes
More people are lighting up with electronic cigarettes. Unlike regular cigarettes, these devices deliver nicotine without all the smoke. But are they safer? Learn what’s known about e-cigarettes and vaping.
Varicella and Pregnancy
Did you have chickenpox as a child? Then you’ve got nothing to worry about from varicella. But if you didn’t, you may not be immune to this infectious disease that can cause complications for a pregnant woman and her baby. Read more to find out why and how to protect yourself.
Vascular Malformations and Hemangiomas
Hemangiomas are growths of blood vessels. They’re also called birthmarks. But they often can't be seen at birth. They usually form in the first few weeks of life.
Ventricular Septal Defect (VSD)
A ventricular septal defect (VSD) is a congenital heart defect. This means that your baby is born with it. A VSD is an opening or hole in the dividing wall (septum) between the 2 lower chambers of the heart (right and left ventricles). VSDs are the most common type of congenital heart defect.
Very Low Birth Weight
Very low birth weight is a term used to describe babies who are born weighing less than 3 pounds, 4 ounces. It is very rare that babies are born this tiny. But the overall rate of very-low-birth-weight babies in the U.S. is going up. This is because more multiple birth babies are being born. Multiples are more likely to be born early and weigh less.
Viral Skin Infections
Detailed information on viral skin infections, including Herpes Zoster (Shingles), Pityriasis Rosea,
Warts, and Molluscum Contagiosum
Visual Screening Overview
Many eye problems happen at an early age, so it is important that your child receives proper eye care (eye exams and visual screening tests).
Vitamin K Deficiency Bleeding in the Newborn
Vitamin K deficiency bleeding is a problem that occurs in some newborns. It happens during the first few days of life. This condition used to be called hemorrhagic disease of the newborn.
Vulvitis in Teens
Vulvitis is an inflammation of the vulva, the soft folds of skin outside the vagina. It is a symptom of a host of diseases, infections, injuries, and allergies.