What to Know About Failure to Thrive

Medically Reviewed by Renee A. Alli, MD on July 16, 2023
3 min read

Your pediatrician may give a failure to thrive diagnosis if your baby or child doesn’t grow or gain weight as expected. There are many factors that can contribute to failure to thrive. Your child is usually monitored over a period of time, with measures taken to promote weight gain and growth.

Failure to thrive is assessed on the basis of the average growth for your child’s age. Infants born prematurely follow slightly different growth patterns on account of their early birth. If lack of growth can be identified and dealt with as early as possible, then your child’s health outcomes are likely to be better. If your child fails to gain weight for an overly long time, it can lead to permanent health problems.‌

There are a number of common reasons an infant or toddler might not gain weight. These include:‌

  • malnutrition
  • malabsorption
  • picky eating
  • genetic factors, such as a tendency for family members to be small in stature
  • a lack of attention from caregivers

‌Doctors often need to rule out child abuse and neglect.‌

In general, the threshold for failure to thrive is below the third to fifth percentiles for weight and height. Your child may also receive a failure to thrive diagnosis if they lose weight consistently, falling from a higher percentile over time. ‌

‌Although many factors contribute to failure to thrive, the bottom line is insufficient nutrition. There used to be two subcategories for failure to thrive diagnoses: The first was organic failure to thrive, which stems from an underlying medical condition. The second was nonorganic failure to thrive, where no known medical condition exists. However, the reality is that a combination of factors is often responsible, so this categorization is outdated.‌‌

Examples of medical conditions that contribute to failure to thrive include:‌

  • severe allergies
  • gastroesophageal reflux
  • cystic fibrosis
  • congenital heart disease
  • genetic syndromes

Examples of nonmedical conditions that contribute to failure to thrive include:

  • inadequate understanding or support of the child’s needs by parents
  • breastfeeding problems
  • failure to introduce solid foods appropriately
  • too much juice or water intake

The most important indicators of failure to thrive are weight and height. If your child suddenly loses weight, it can be a sign of failure to thrive.‌‌

In addition to the obvious weight- and height-related indications, the following signs may mean that your child has failure to thrive:‌

  • a smaller head circumference
  • milestone delays like not rolling over, sitting, standing, or walking when expected‌
  • delays in the development of mental and social skills‌

‌As your child gets older, they may exhibit delays in puberty.

Your doctor assesses your child for potential causes of failure to thrive so that they can treat the underlying concern.‌

Health problems. If a medical problem is to blame, your doctor wants to diagnose the health condition so that your child can receive appropriate treatment. Approaches used for treating failure to thrive may include: ‌

  • physical therapy
  • occupational therapy
  • assistance from a dietician
  • a feeding tube if an inability to eat and drink is a factor‌

Environmental concerns. Your doctor may also ask about your home life to pinpoint any environmental factors that contribute. These might include your family’s eating habits and mealtimes and your child’s routine. It is important to determine whether failure to thrive results from medical problems or factors in the environment such as abuse or neglect.‌

Common environmental factors include:‌

  • a lack of emotional support and love from a caregiver or parent 
  • rejection or hostility from a caregiver or parent 
  • inadequate food and unsuitable living conditions
  • infections, parasites, or toxins‌
  • poor eating habits‌

If environmental factors are contributing to failure to thrive, your doctor may provide educational materials to help you with making lifestyle changes.‌

It may take some trial and error to come up with a solution that helps your child with their specific needs. In some cases, your child may need to be hospitalized for monitoring prior to more comprehensive treatment.‌

If your doctor is monitoring your child’s lack of weight gain, you may be tempted to supplement your child’s diet or try home remedies. You should always talk to your doctor before you use any supplemental products for treating failure to thrive.