A babysitter is someone who provides occasional child care for a few hours at a time. Teenage babysitters often provide babysitting services for a few hours at a time.

Battered Child Syndrome

Battered child syndrome (BCS) refers to non-accidental injuries sustained by a child as a result of physical abuse, usually inflicted by an adult caregiver.

Bayley Scales of Infant Development

The Bayley Scales of Infant Development (BSID) measure the mental and motor development and test the behavior of infants from one to 42 months of age.


Bed-wetting, also called enuresis, is the unintentional discharge of urine during sleep. Although most children between the ages of three and five begin to stay dry at night, the age at which children are physically and emotionally ready to maintain complete bladder control varies.

Beery-Buktenica Test

The Beery-Buktenica visual-motor integration test is a neuropsychological test that analyzes visual construction skills. It identifies problems with visual perception, motor coordination, and visual-motor integration such as hand-eye coordination.


Bejel, also known as endemic syphilis, is a chronic but curable disease that is seen mostly in children in dry regions, such as parts of Africa (Sudan, southern Rhodesia, and South Africa), parts of the Middle East (among nomadic/Bedouin tribes of Saudi Arabia, Iraq, and Syria), and parts of Asia (Turkey, southeast Asia, and the western Pacific). Unlike venereal syphilis, endemic syphilis is not sexually transmitted.

Bell's Palsy

The National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institute of Health (NIH), defines Bell's palsy as "a form of facial paralysis resulting from damage to the seventh (facial) cranial nerve." This condition is considered to be normally a transient phenomenon and not permanently disabling. It is named for Sir Charles Bell, a Scottish surgeon who, over two hundred years ago, did much of the earliest research regarding the anatomy and pathology of the cranial nerves.

Biliary Atresia

Biliary atresia is the congenital failure of a fetus to develop an adequate pathway for bile to drain from the liver to the intestine.

Bilingualism/Bilingual Education

Bilingualism is the ability to communicate in two different languages. Bilingual education is the use of two different languages in classroom instruction.

Bilirubin Test

A bilirubin test is a diagnostic blood test performed to measure levels of bile pigment in an individual's blood serum and to help evaluate liver function.

Binge Eating Disorder

Binge eating disorder (BED) is characterized by loss of control over eating behaviors. The binge eater consumes unnaturally large amounts of food in a short time period, but unlike a bulimic, does not regularly engage in any inappropriate weight-reducing behaviors such as excessive exercise, induced vomiting, or taking laxatives following the binge episodes.

Bipolar Disorder

Bipolar, or manic-depressive disorder, is a mood disorder that causes radical emotional changes and mood swings, from manic highs to depressive lows. The majority of bipolar individuals experience alternating episodes of mania and depression.

Birth Order

Birth order is the chronological order of sibling births in a family.


Birthmarks are areas of discolored and raised spots found on the skin. Birthmarks are groups of malformed pigment cells or blood vessels.

Bites and Stings

Humans can be injured by the bites or stings of many kinds of insects and animals. These range from the bites from a neighbor's dog or cat to bites from fellow humans and spiders to the stings from bees, wasps, snakes, and marine animals such as jellyfish and stingrays.

Blood Sugar Tests

Blood sugar or plasma glucose tests are used to determine the concentration of glucose in blood. These tests are used to detect an increased blood glucose (hyperglycemia) or a decreased blood glucose (hypoglycemia).


Bonding is the formation of a mutual emotional and psychological closeness between parents (or primary caregivers) and their newborn child. Babies usually bond with their parents in the minutes, hours, or days following birth.


Botulism is an acute, progressive condition caused by botulinum toxin, a natural poison produced by the spore-forming bacteria Clostridium botulinum. Exposure to the botulinum toxin usually occurs from eating contaminated food although, in infants, it may be caused by specific types of clostridia obtained from soil or inhaled spores, causing growth of the bacteria in the infant's intestine.

Brachial Plexopathy, Obstetric

Brachial plexopathy is any injury to the brachial plexus—the nerve bundles located on each side of the neck that give rise to the individual nerves controlling the muscles of the shoulders, arms, and hands.

Breast Development

A newborn baby has nipples, areolas, and the beginnings of breast tissue, but most of breast development occurs in two different periods of time in a woman's life: first in puberty, then during pregnancy. Breast development is a vital part of puberty in the human female.

Breath Holding Spells

Breath holding spells are episodes of brief, involuntary cessations of breathing that occur in children in response to stimuli such as anger, frustration, fear, or injury.

Breech Birth

Breech birth is the delivery of a fetus (unborn baby) in a bottom- or foot-first position. Between 3 to 4 percent of fetuses start labor in the breech position, which is a potentially dangerous situation.


Bronchiolitis is a lung infection that affects children of any age; however, it is much more severe when it occurs in young infants.


Bronchitis is an inflammation of the air passages between the nose and the lungs, including the windpipe or trachea and the larger air tubes of the lung that bring air in from the trachea (bronchi). Bronchitis can either be of brief duration (acute) or have a long course (chronic).


Bruises, or ecchymoses, are a discoloration and tenderness of the skin or mucous membranes due to the leakage of blood from an injured blood vessel into the tissues. Purpura refers to bruising as the result of a disease condition.

Bruton's Agammaglobulinemia

Bruton's agammaglobulinemia is a disorder that is present at birth (congenital) and is characterized by low or completely absent levels of immunoglobulins in the bloodstream. Bruton's agammaglobulinemia is also known as X-linked agammaglobulinemia (XLA).

Bulimia Nervosa

Bulimia nervosa is a serious and sometimes life-threatening eating disorder affecting mainly young women. People with bulimia, known as bulimics, consume large amounts of food (binge) and then try to rid themselves of the food and calories (purge) by fasting, excessive exercise, vomiting, or using laxatives.


Bullies are aggressive children who repeatedly physically or emotionally abuse, torment, or victimize smaller, weaker, or younger children.


Burns are injuries to tissues that are caused by heat, friction, electricity, radiation, or chemicals.