Diseases & Conditions


Failure to Thrive

Failure to thrive is a delay in physical growth and weight gain that can lead to delays in development and maturation.

Failure to thrive is a diagnosis given to children who are consistently underweight or who do not gain weight for unclear reasons. There are many causes. Most causes involve environmental and social factors that interact to keep the child from getting the nutrition the child needs. Occasionally, medical disorders prevent a child from growing normally.

Many environmental and social factors can be responsible. Parental neglect or abuse, parental mental health disorders, and chaotic family situations in which routine, nutritious meals are insufficiently provided, may all blunt a child's appetite and intake of food. The amount of money a family has to spend on food and the nutritional value of the food they buy also affect growth. Inadequate intake of food may reflect inadequate parenting and environmental stimulation.

Sometimes failure to thrive is caused by a medical disorder in the child. The disorder can be as minor as difficulty chewing or swallowing (as with a cleft lip or cleft palate). Medical disorders, such as gastroesophageal reflux, narrowing of the esophagus, or intestinal malabsorption, may also affect a child's ability to retain, absorb, or process food. Infection, tumor, hormonal or metabolic disorders (such as diabetes or cystic fibrosis), heart disease, kidney disease, genetic disorders, and human immunodeficiency virus (HIV) infection are other physical reasons for failure to thrive.


Doctors diagnose failure to thrive when a child's weight or rate of growth is well below what it should be when compared with past measurements or standard height-weight charts (see Height and Weight Charts for Boys and Girls ). If the rate of growth is adequate, the child may be small for his or her age but still growing normally.

To determine why a child may be failing to thrive, doctors ask parents specific questions about feeding; bowel habits; social, emotional, and financial stability of the family, which might affect the child's access to food; and illnesses that the child has had or that run in the family. The doctor examines the child, looking for signs of conditions that could explain the child's growth delay. The doctor makes decisions about blood and urine tests and x-rays based on this evaluation. More extensive testing is performed only if the doctor suspects an underlying disease.

Treatment and Prognosis

Treatment depends on the cause. If a medical disorder is found, specific treatment is given. Otherwise, treatment depends on how far below normal the child's weight is. Mild to moderate failure to thrive is treated with nutritious, high-calorie feedings given on a regular schedule. Parents may be counseled about family interactions that are damaging to the child and about financial and social resources available to them. Severe failure to thrive is treated in the hospital where social workers, nutritionists, feeding specialists, psychiatrists, and other specialists work together to determine the most likely causes of the child's failure to thrive and the best approach to feeding.

Because the first year of life is important for brain development, children who become undernourished during this time may fall permanently behind their peers, even if their physical growth improves. In about half of these children, mental development, especially verbal skills, remains below normal, and these children often have social and emotional problems in adulthood.

Last full review/revision January 2007 by Elizabeth J. Palumbo, MD

Source: The Merck Manual Home Edition