Undescended Testes

Also known as cryptorchidism, undescended testes is a congenital condition characterized by testicles that do not follow the normal developmental pattern of moving into the scrotum before birth.


Vaccination introduces a vaccine into the body to produce immunity and prevent specific diseases.


Vasculitides is the plural of the word vasculitis, which may be used to describe any disorder characterized by inflammation of the blood or lymph vessels. Vasculitis is not a distinctive disease in its own right, but rather a symptom or characteristic of a number of different diseases.


Vegetarianism is the voluntary abstinence from eating meat. Vegetarians refrain from eating meat for various reasons, including religious, health, and ethical ones.

Vesicoureteral Reflux

Vesicoureteral reflux (VUR) is a condition in which urine flows from the bladder, back up the ureter, and back into the kidneys.

Video Games

Video games are electronic, interactive games known for their vibrant colors, sound effects, and complex graphics.

Vitamin D Deficiency

Vitamin D deficiency exists when the concentration of 25-hydroxy-vitamin D (25-OH-D) in the blood serum occurs at 12 nanograms/milliliter (ng/ml) or less. This is one-half to one-fourth the amount normally present.


Vitamins are organic components in food that are needed in very small amounts for growth and for maintaining good health. The vitamins include vitamins D, E, A, and K (fat-soluble vitamins), and folate (folic acid), vitamin B12, biotin, vitamin B6, niacin, thiamin, riboflavin, pantothenic acid, and vitamin C (ascorbic acid) (water-soluble vitamins).

Vocal Cord Dysfunction

Vocal cord dysfunction (VCD) is a disorder that occurs when the vocal cords move toward each other when a person breathes, narrowing the airway and causing wheezing and difficulty breathing. VCD is also called paradoxical vocal cord motion (PVCM).

Von Willebrand Disease

Von Willebrand disease is caused by a deficiency or an abnormality in a protein called von Willebrand factor and is characterized by prolonged bleeding.


Warts are small, benign growths caused by a viral infection of the skin or mucous membrane. The virus infects the surface layer.

Wechsler Intelligence Test

The Wechsler intelligence tests are a widely used series of intelligence tests developed by clinical psychologist David Wechsler.

Well-Baby Examination

Well-baby examinations are scheduled regularly during the first two years of life due to the rapid growth and change that occurs during infancy. During each visit the pediatrician monitors, advises, and answers questions on a baby's growth and development.

Whooping Cough

Whooping cough, also known as pertussis, is a highly contagious disease which causes classic spasms (paroxysms) of uncontrollable coughing, followed by a sharp, high-pitched intake of air which creates the characteristic whoop that is reflected in the disease's name.

Williams Syndrome

A rare congenital (present from birth) genetic disorder that results in physical and developmental delays and problems.

Wilms' Tumor

Wilms' tumor is a cancerous tumor of the kidney that usually occurs in young children.

Wiskott-Aldrich Syndrome

Wiskott-Aldrich syndrome (WAS) is a rare inherited disorder marked by a low level of blood platelets, eczema, recurrent infections, and a high risk of leukemia or lymph node tumors.

Working Mothers

Working mothers, as a label, refers to women who are mothers and who work outside the home for income in addition to the work they perform at home in raising their children.


A wound occurs when the integrity of any tissue is compromised (e.g. skin breaks, muscle tears, burns, or bone fractures).


Wryneck, also called twisted neck or torticollis, is a deformity in which the neck is twisted and held at an angle to one side. A congenital (present at birth) form called congenital torticollis is the most common type of wryneck seen in children.

X Rays

X rays are electromagnetic radiation that differentially penetrates structures within the body and creates images of these structures on photographic film or a fluorescent screen. These images are called diagnostic x rays.


The term "yoga" comes from a Sanskrit word meaning "union." Yoga combines physical exercises, mental meditation, and breathing techniques to strengthen the muscles and relieve stress.