Abandonment is a legal term describing the failure of a non-custodial parent to provide support to his or her children according to the terms approved by a court of law. In common use, abandonment refers to the desertion of a child by a parent.

Abdominal Wall Defects

Abdominal wall defects are birth (congenital) defects that allow the stomach or intestines to protrude.


Acetaminophen is a medicine used to relieve pain and reduce fever.


Acne is a skin disorder that leads to an outbreak of lesions called pimples or "zits." The most common form of the disease is called acne vulgaris—the rash that affects many adolescents. Acne vulgaris is triggered by the hormonal changes that occur in puberty.

Acromegaly and Gigantism

Acromegaly is a disease in which an abnormality in the pituitary gland leads to an oversecretion of growth hormone. In adults, this condition results in an enlargement of bones; in children, the abnormality results in excessive height and is called gigantism.

Acting Out

Acting out is defined as the release of out-of-control aggressive or sexual impulses in order to gain relief from tension or anxiety. Such impulses often result in antisocial or delinquent behaviors.

Adaptive Behavior Scales for Infants and Early Childhood

Adaptive behavior scales are standardized tests used to describe and evaluate the behavior of infants, toddlers, and preschoolers, especially those at risk for communication delays and behavior impairments.


Addiction is a physical or mental dependence on a behavior or substance that a person feels powerless to stop.

Adenoid Hyperplasia

Adenoid hyperplasia is an enlargement of the lymph glands located above the back of the mouth.

Adenovirus Infections

Adenoviruses are small infectious agents that cause upper respiratory tract infections, conjunctivitis, and other infections in humans.

Adjustment Disorders

Adjustment disorder is an umbrella term for several mental states characterized by noticeable behavioral and/or emotional symptoms. In order to be classified as an adjustment disorder, these symptoms must be shown to be a response to an identifiable stressor that has occurred within the past three months.


Sometimes referred to as teenage years, youth, or puberty, adolescence is the transitional period between childhood and maturity, occurring roughly between the ages of 10 and 20.


Adoption is the practice in which an adult assumes the role of parent for a child who is not the adult's biological offspring. The process usually involves some legal paperwork.

Aggressive Behavior

Aggressive behavior is reactionary and impulsive behavior that often results in breaking household rules or the law; aggressive behavior is violent and unpredictable.


Albinism is an inherited condition that is present at birth. It is characterized by a lack of melanin, the pigment that normally gives color to the skin, hair, and eyes.


Allergic Purpura

Allergic purpura (AP), a form of vasculitis (inflammation of the blood vessels), is a disease characterized by inflammation of the small arterial vessels (capillaries) in the skin, kidneys, and intestinal tract. Symptoms include a purple spotted skin rash, abdominal pain, gastrointestinal upsets, and joint inflammation, swelling, and pain.

Allergic Rhinitis

Allergic rhinitis, more commonly referred to as hay fever, is an inflammation of the nasal passages caused by allergic reaction to airborne substances.


Allergies are abnormal reactions of the immune system that occur in response to otherwise harmless substances.

Allergy Shots

Allergy shots, also called immunotherapy, are a form of treatment that reduces a person's allergic reaction to a particular allergen. Allergy shots can reduce symptoms of allergic rhinitis (hay fever) and allergic asthma.

Allergy Tests

Allergy tests evaluate levels of allergic sensitivity to commonly encountered allergens, which may be foods, pollen, chemicals, or other substances in the environment.

Allowance and Money Management

An allowance is money earned or given to a child at regular intervals to teach the child how to manage money.


Alopecia is the partial or complete loss of hair—especially on the scalp—either in patches (alopecia areata), on the entire head (alopecia totalis), or over the entire body (alopecia universalis).

Alpha-Fetoprotein Test

The alpha-fetoprotein (AFP) test is a blood test that is performed during pregnancy to screen the fetus for certain conditions; it is also used to screen for certain diseases in infants and children. The screening test measures the level of AFP in the mother's blood and indicates the probability that the fetus has one of several serious birth defects.

Alternative School

An alternative school is an educational setting designed to accommodate educational, behavioral, and/or medical needs of children and adolescents that cannot be adequately addressed in a traditional school environment.


Amblyopia refers to diminished vision in either one or both eyes, for which no cause can be discovered upon examination of the eye. Amblyopia is the medical term used when the vision in one of the eyes is reduced because the eye and the brain are not working together properly.


Amenorrhea is the medical term for the absence of menstruation. There are two types of amenorrhea, primary and secondary.


Amniocentesis is a procedure used to diagnose fetal defects in the early second trimester of pregnancy. A sample of the amniotic fluid, which surrounds a fetus in the womb, is collected through a pregnant woman's abdomen using a needle and syringe.

Anabolic Steroids

Anabolic steroids are compounds, derived from testosterone, which promote tissue growth and repair. Because they have been used improperly by body builders and other athletes, they are controlled substances under United States federal law.


Analgesics are those drugs whose primary purpose is pain relief. The primary classes of analgesics are the narcotics, including additional agents that are chemically based on the morphine molecule but have minimal abuse potential; nonsteroidal anti-inflammatory drugs (NSAIDs) including the salicylates; and acetaminophen.


Anaphylaxis is a severe, sudden, and potentially fatal allergic reaction to a foreign substance or antigen that affects multiple systems of the body.

Anatomical Age

Anatomical age is the numerical assessment of a child's physical growth in relation to the statistical average based on the child's chronological age.


Anemia is a blood disorder characterized by abnormally low levels of healthy red blood cells (RBCs) or reduced hemoglobin (Hgb), the iron-bearing protein in red blood cells that delivers oxygen to tissues throughout the body. Reduced blood cell volume (hematocrit) is also considered anemia.

Angelman's Syndrome

Angelman's syndrome is a relatively rare genetic disorder that causes a variety of neurological problems, including developmental delay, seizures, speech impairment, and problems with movement and balance.

Animal Bite Infections

Animal bite infections develop in humans when an animal's teeth break the skin and introduce saliva containing disease organisms below the skin surface. The saliva of dogs, cats, ferrets, and rabbits is known to contain a wide variety of bacteria.

Anorexia Nervosa

Anorexia nervosa is an eating disorder characterized by self-starvation, unrealistic fear of weight gain, and conspicuous distortion of body image.

Antenatal Testing

Antenatal testing describes procedures performed during pregnancy to detect health problems in the growing fetus; establish characteristics such as fetal age, sex, or weight; or diagnose any material conditions that may affect fetal development.

Antepartum Testing

Antepartum testing involves the use of electronic fetal monitoring (EFM) or ultrasound (US) to assess fetal well-being as determined by the fetal heart rate (FHR) and other characteristics during the antepartal period, which is the period spanning from conception to labor. Antepartum tests include the nonstress test (NST), modified biophysical profile (MBPP), contraction stress test (CST), oxytocin contraction stress test (OCT), biophysical profile (BPP), doppler flow studies, amniocentesis, cordocentesis, and fetal echocardiography.

Antiacne Drugs

Acne is a skin disorder that leads to an outbreak of lesions called pimples or "zits." The most common form of the disease in adolescents is called acne vulgaris. Antiacne drugs are the medicines that help clear up the pimples, blackheads, whiteheads, and more severe forms of lesions that occur when a teen has acne.

Antiasthmatic Drugs

Antiasthmatic drugs are medicines that treat or prevent asthma attacks.


Antibiotics are used for treatment or prevention of bacterial infection. They may be informally defined as the subgroup of anti-infectives that are derived from bacterial sources and are used to treat bacterial infections.

Antibiotics, Topical

Topical antibiotics are medicines applied to the skin to kill bacteria.


An antidepressant is a medication used primarily in the treatment of depression. Depression can occur if some of the chemicals called neurotransmitters in the brain are not functioning effectively.


Antiepileptic drugs are medicines that reduce the frequency of epileptic seizures.


Antihistamines are drugs used to treat the symptoms of allergies and allergic rhinitis by blocking the action of histamine, a chemical released by the immune system in allergic reactions.

Antisocial Behavior

Antisocial behaviors are disruptive acts characterized by covert and overt hostility and intentional aggression toward others. Antisocial behaviors exist along a severity continuum and include repeated violations of social rules, defiance of authority and of the rights of others, deceitfulness, theft, and reckless disregard for self and others.

Antisocial Personality Disorder

Antisocial behavior is that which is verbally or physically harmful to other people, animals, or property, including behavior that severely violates social expectations for a given environment. Antisocial personality disorder in adults is also referred to as sociopathy or psychopathy.

Antiviral Drugs

Viruses represent a large group of infective agents that are composed of a core of nucleic acids, either RNA or DNA, surrounded by a layer of protein. They are not really living organisms according to general understanding, since they lack the cell membrane that is associated with living cells.


Anxiety is a condition of persistent and uncontrollable nervousness, stress, and worry that is triggered by anticipation of future events, memories of past events, or ruminations over day-to-day events, both trivial and major, with disproportionate fears of catastrophic consequences.

Apgar Testing

The Apgar scoring system evaluates the physical condition of the newborn at one minute after birth and again at five minutes after birth. The newborn receives a total score (Apgar score) that ranges from 0 to 10 based on rating color, heart rate, respiratory effort, muscle tone, and reflex irritability.

Apnea of Infancy

Apnea is a temporary cessation of breathing. Among children, this is most common in newborns.


Appendicitis is an inflammation of the appendix, which is the small, finger-shaped pouch attached to the beginning of the large intestine on the lower-right side of the abdomen. Appendicitis is a medical emergency, and if left untreated, the appendix may rupture and cause a potentially fatal infection.

Arteriovenous Fistula

An arteriovenous fistula is an abnormal channel or passage between an artery and a vein.

Asphyxia Neonatorum

Asphyxia neonatorum is respiratory failure in the newborn, a condition caused by the inadequate intake of oxygen before, during, or just after birth.


Assessment is a process of gathering and documenting information about the achievement, skills, abilities, and personality variables of an individual.


Asthma is a chronic (long-lasting) inflammatory disease of the airways. In people susceptible to asthma, this inflammation causes the airways to narrow periodically.

Ataxia Telangiectasia/Chromosome Breakage Disorders

Ataxia telangiectasia (A-T), also called Louis-Bar syndrome or cerebello-oculocutaneous telangiectasia, is a rare, inherited disease that attacks the neurological and immune systems of children. A-T is a recessive disorder, meaning that it affects children who carry two copies of a defective (mutated) A-T gene, one copy from each parent.

Atopic Dermatitis

Atopic dermatitis (AD) is a chronic skin disorder associated with biochemical abnormalities in the patient's body tissues and immune system. It is characterized by inflammation, itching, weepy skin lesions, and an individual or family history of asthma, hay fever, food allergies, or similar allergic disorders.

Atrial Septal Defect

An atrial septal defect (ASD) is an abnormal opening in the muscular wall separating the left and right upper chambers (atria) of the heart.

Attachment Between Infant and Caregiver

Infant attachment is the deep emotional connection that an infant forms with his or her primary caregiver, often the mother. It is a tie that binds them together, endures over time, and leads the infant to experience pleasure, joy, safety, and comfort in the caregiver's company.

Attention-Deficit/Hyperactivity Disorder (AD/HD)

Attention-deficit/hyperactivity disorder (AD/HD) is a neurobiological disorder characterized by hyperactivity, impulsive behavior, and the inability to remain focused on tasks or activities.


The purpose of audiometry is to establish an individual's range of hearing. It is most often performed when hearing loss is suspected.

Auditory Discrimination Test

Auditory discrimination is a central auditory processing skill that involves the ability to differentiate among phonemes—the smallest significant units of sound in a language. Phonemes are combined into words.


Autism is a severely incapacitating developmental disorder of brain function characterized by three major types of symptoms: impaired social interaction, problems with verbal and nonverbal communication, and unusual or severely limited activities and interests.