Growth is characterized by increases in height and weight as well as bodily changes that occur as a person develops. Other aspects of growth include the growth of hair and bones and the transition of baby teeth to adult teeth.
Human growth can be tracked through various stages beginning with conception and continuing as the fetus develops. Once born, a healthy human will progress from a newborn/infant (zero months to one year), to a toddler (1-4 years), child (5-12 years), adolescent (13-19 years), young adult (20-35 years), adult (35-40), middle-aged adult (40-59), and finally to an elderly adult or senior citizen (60+ years).
Biological development or growth begins when a child is conceived. Conception happens when sperm from a man fertilizes an egg in a female resulting in a human embryo which develops and grows for nine month's in the mother's womb.
According to the U.S. Centers for Disease Control and Prevention (CDC), childhood is a time of rapid growth and cognitive, social, and emotional development that is accompanied by changes in organ system functioning, metabolic capabilities, physical size, and behavior.
Human growth may be affected by heredity, gender, illness and medications, nutrition, hormones, and psychosocial environment, among other factors. A warning sign of a growth abnormality is below or above average height and/or weight. During the first year of life, an infant should grow an average of 7-10 inches. During the second year, a toddler will grow approximately five inches. During the third year, toddlers grow three inches on average. From age four years until puberty, growth should be at least two inches/year. During puberty, girls may grow 2.5-4.5 inches/year. Puberty occurs later in boys and is usually characterized by a growth of 3-5 inches/year. After puberty, there is little to no additional growth of bones.
Growth problems may be genetic or acquired. Genetic growth abnormalities can be generally categorized as overgrowth disorders or undergrowth disorders. Overgrowth syndromes can be diagnosed by unusually large size at birth, excessive postnatal growth, and increased weight, increased length, and/or increased head circumference. There is an increased risk of cancer in a number of the overgrowth syndromes.
Common overgrowth syndromes include Bannayan-Riley-Ruvalcaba syndrome, fragile X syndrome, gigantism, hemihyperplasia, Maffucci syndrome, neurofibromatosis, Proteus syndrome, and Weaver syndrome. A common cause of overgrowth syndromes is the overproduction of growth hormone by the pituitary gland before adolescence and a distinctive pattern of overgrowth called acromegaly.
Undergrowth syndromes may be caused by musculoskeletal and metabolic diseases, including those that cause alterations in the skeleton. Examples of undergrowth syndromes include dwarfism, Ellis Van Creveld syndrome, and Russell Silver syndrome.
Human growth disorders may affect growth symmetrically or may act regionally affecting the normal proportionality of the human body. Growth disorders may occur in infants, kids, or teens and may prevent them from meeting expectations of growth, such as failure to gain height and weight in young children to short stature or delayed sexual development in teens. Diseases of the kidneys, heart, gastrointestinal tract, lungs, bones, or other body systems may affect growth.
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pituitary disorder diagnosis, pituitary gland, Russell Silver syndrome, sleep apnea, thyroxine, Sotos syndrome, Turner's syndrome.
types of the disease
General: The endocrine system helps control growth and development throughout the body. It consists of small organs that regulate body functions through the release of hormones.
The pituitary gland is a small, oval-shaped organ at the base of the brain that releases a variety of hormones into the blood stream, including growth hormone (GH). Growth hormone is a protein hormone that stimulates growth and cell reproduction in humans and other animals. Once in the blood, GH travels to bone, muscle, and other tissues where it has many effects. The hypothalamus, a small structure located at the base of the brain just above the pituitary gland, controls the release of growth hormone by the pituitary gland. The principal stimulator of growth hormone secretion is called growth hormone-releasing hormone (GHRH).
In children, GH stimulates linear growth (height) and contributes to the development of muscle and bone and the distribution of fat throughout the body. In adults, GH affects energy, muscle strength, bone health, and psychological well-being. Having either too much or too little GH can cause health problems, such as acromegaly, which is excessive growth. Excess GH in adults is most common in middle-aged men and women.
Acromegaly: Acromegaly is a hormonal disorder that occurs when the pituitary gland in the brain, which makes GH, produces excessive amounts of GH. The excess GH may come from benign, or noncancerous, tumors on the pituitary called adenomas. Symptoms of acromegaly may appear at any age although it is most often diagnosed in middle-aged adults. Acromegaly is treatable in most patients; however, because of its slow onset, it often is not diagnosed early or correctly and may lead to serious illness and premature death. According to the National Endocrine and Metabolic Diseases Information Service, the most serious health consequences of acromegaly are type 2 diabetes, high blood pressure, increased risk of cardiovascular disease, and arthritis. Patients with acromegaly may also have an increased risk for colon polyps, which can develop into colon cancer. According to The Hormone Foundation, approximately 60 out of every one million Americans have acromegaly.
Dwarfism: Dwarfism is generally defined as an abnormally short stature, usually an adult height of four feet, 10 inches or less. Adult height among people with dwarfism ranges from two feet eight inches to four feet eight inches. More than 200 different conditions can cause dwarfism. Achondroplasia, a genetic condition that causes the arms and legs to be short in comparison to the head and trunk, causes about 70% of all dwarfism. Other genetic conditions, kidney disease, and problems with metabolism or hormones can also cause short stature. Achondroplasia occurs most often in families where both parents are of average height; 85% of children with achondroplasia are born to average-size parents.
Ellis-van Creveld syndrome: Ellis-van Creveld syndrome, or chondroectodermal dysplasia, is a rare genetic disorder associated with short-limb dwarfism, polydactyly (additional fingers or toes), malformation of the bones of the wrist, dystrophy of the fingernails, partial hare-lip, cardiac malformation, and often prenatal eruption of the teeth.
Fragile x syndrome: Fragile X syndrome is the most common form of inherited mental retardation. A problem with a specific gene, called the Fragile X Mental Retardation 1 (FMR1)
gene, causes the disease. Normally, the gene makes a protein needed for brain development. The mutation causes a person to make little or none of the protein, which results in the symptoms of fragile X. People with only a small change in the gene might not show any signs of fragile X; people with bigger changes may have severe symptoms. Common traits of fragile X syndrome include: intelligence problems, ranging from learning disabilities to severe mental retardation; social and emotional problems, such as aggression in boys or shyness in girls; and speech and language problems, especially in boys.
Gigantism: Gigantism is the result of an excessive secretion of growth hormone during childhood before the closure of the bone growth plates; it is characterized by the overgrowth of long bones and a very tall stature. The excess GH secretion is frequently caused by a benign (noncancerous) pituitary gland tumor. Underlying medical conditions, such as multiple endocrine neoplasia type 1 (MEN-1), McCune-Albright syndrome (MAS), neurofibromatosis, or Carney complex, may also cause gigantism. Gigantism is inherited and occurs in fewer than 100 children in the United States.
Growth hormone deficiency (GHD): Growth hormone deficiency (GHD) is the condition of having too little growth hormone (GH) characterized by abnormally short stature with normal body proportions. Growth hormone deficiency can be categorized as either congenital (present at birth) or acquired. In the United States, it is estimated that about 20,000 children and 35,000 adults have GHD.
Neurofibromatosis: Neurofibromatosis is a genetic disorder of the nervous system that affects how nerve cells form and grow, usually causing tumors to grow on nerves. Neurofibromatosis may be inherited or it can happen because of a genetic mutation. There are three types of neurofibromatosis: type 1 (NF1) causes skin changes and deformed bones and usually starts at birth; type 2 (NF2) causes hearing loss, ringing in the ears, and poor balance and often starts in the teen years; and schwannomatosis, which causes intense pain and is the rarest type.
Panhypopituitarism (hypopituitarism): Hypopituitarism is a rare condition caused by low levels of pituitary hormones. The pituitary gland is a small bean-shaped gland located at the base of the brain that secretes hormones that influence nearly every part of the body. In hypopituitarism, there is a short supply of one or more of these pituitary hormones. This deficiency may affect growth, blood pressure, and reproduction.
Russell Silver syndrome: Russell-Silver syndrome, which presents at birth, results in poor growth, low birth weight, short height, and differences in the size of the two sides of the body. Other symptoms include: delayed bone age, wide forehead with a small triangle-shaped face, small, narrow chin, arms and legs of differing lengths, curving of the pinky toward the ring finger, short, stubby fingers and toes, "cafe-au-lait" (flat, pigmented spots on the skin that are named for the French term for coffee (café) with milk (lait) because of their light tan color) spots, arm span less than height (short arms), kidney problems (hydronephrosis, renal tubular acidosis, posterior urethral valves, horseshoe kidney), gastroesophageal reflux disease, swelling of the esophagus (food pipe), and failure to thrive. An estimated 7-10% of patients with this syndrome have a defect in a gene called the maternal uniparental disomy (UPD) for chromosome 7. In the other 90-93% percent of patients, a cause cannot be identified; most cases occur in a person whose family has no history of the disease. Males and females are equally affected.
Sotos syndrome: Sotos syndrome, also called cerebral gigantism, is a rare genetic disorder that is associated with excessive physical growth during the first 2-3 years of life and may be accompanied by mild mental retardation, delayed motor, cognitive, and social development, low muscle tone, and speech impairments. Children with Sotos syndrome are typically large at birth and are often taller, heavier, and have larger heads than is normal for their age. Most cases of Sotos syndrome occur sporadically. However, familial cases have also been reported.