Failure to Thrive
Slower-than-expected weight gain and growth in childhood
Quick Facts
- Type: Growth and nutrition concern
- Most common in: Infants and young children
- Key sign: Falling growth or low weight for age
- Goal of care: Find the cause and support catch-up growth
Overview
Failure to thrive, also called faltering growth, describes a child who is not gaining weight or growing as expected for their age. It is not a single disease but a sign that a child is not getting or using enough nutrition to support normal development. Doctors identify it by plotting a child's weight and length on standard growth charts and watching the pattern over time.
Most cases relate to not taking in enough calories, but sometimes an underlying medical condition is responsible. The earlier the cause is found, the sooner a child can catch up. With appropriate support, the great majority of children improve, gain weight, and resume healthy growth.
Symptoms
The main feature is poor growth, but other signs may accompany it:
- Weight or growth that falls below or drops across percentile lines on the growth chart
- Slower-than-expected gains in length or head size
- Lack of expected developmental milestones in some children
- Low energy, irritability, or excessive sleepiness
- Feeding difficulties or poor appetite
A single low measurement is not enough; the concern is a sustained pattern of inadequate growth over time.
Causes
Causes generally fall into a few broad groups, and more than one may be present:
- Not enough calories taken in: Feeding problems, difficulty breastfeeding or preparing formula, a limited diet, or, in some families, limited access to food.
- Poor absorption: Conditions such as celiac disease, food allergies, or chronic diarrhea that prevent nutrients from being absorbed.
- Increased needs or losses: Heart, lung, kidney, or other chronic illnesses, frequent infections, or metabolic conditions that burn more energy.
Emotional, social, and feeding-environment factors can also play a role and are addressed as part of care, without blame.
Risk Factors
- Premature birth or low birth weight
- Feeding difficulties, including problems with sucking or swallowing
- Chronic medical conditions affecting the heart, lungs, gut, or kidneys
- Food allergies or intolerances
- Family stress, limited food access, or challenges with feeding routines
Diagnosis
Evaluation focuses on confirming the growth pattern and finding the cause:
- Growth tracking: Reviewing measurements over time on standard charts.
- History and feeding review: Asking about diet, feeding routines, illnesses, and family circumstances.
- Physical exam: Looking for signs of underlying illness or nutritional deficiency.
- Targeted tests: Blood or stool tests, or other studies, only when something specific is suspected.
Treatment
Treatment addresses the underlying cause and helps the child catch up on growth.
- Nutritional support: Increasing calories and nutrients through changes to feeding, higher-energy foods or formulas, and sometimes guidance from a dietitian.
- Treating medical causes: Managing any condition found, such as reflux, allergy, or infection.
- Feeding support: Help with feeding techniques, mealtime routines, and, when needed, feeding or swallowing therapy.
- Family support: Connecting families with resources for food access and parenting support when helpful.
- Monitoring: Regular follow-up to track weight gain and growth.
When to See a Doctor
Contact your child's doctor if your baby or child is not gaining weight, seems to be losing weight, or is feeding poorly. Seek prompt care if a child is very lethargic, refusing to feed, becoming dehydrated (few wet diapers, dry mouth, no tears), or showing signs of serious illness. Early evaluation helps identify the cause and supports healthy catch-up growth.
Frequently Asked Questions
Does failure to thrive mean a parent is doing something wrong?
No. Failure to thrive is a medical sign with many possible causes, including underlying illness, feeding difficulties, or limited food access. The goal of care is to find and address the cause supportively, not to assign blame.
Will a child with failure to thrive catch up?
Most children catch up once the cause is identified and addressed, whether through better nutrition, treating a medical condition, or feeding support. Regular follow-up helps confirm that growth is back on track.
What causes failure to thrive?
The most common cause is not taking in enough calories, but it can also result from poor absorption of nutrients (such as in celiac disease) or from chronic illnesses that increase energy needs. Often several factors combine.
How is failure to thrive diagnosed?
Doctors plot a child's weight and length on growth charts over time and review feeding, history, and a physical exam. Specific blood or other tests are done only when an underlying condition is suspected.
When should I worry about my baby's weight?
Contact your doctor if your baby is not gaining weight, is losing weight, or feeds poorly. Seek urgent care if your child is very sleepy, refusing feeds, or showing signs of dehydration such as few wet diapers.
References
- American Academy of Pediatrics (HealthyChildren.org). Failure to Thrive.
- MedlinePlus, U.S. National Library of Medicine. Failure to thrive.
- Mayo Clinic. Failure to thrive.
- Centers for Disease Control and Prevention (CDC). Child Growth Charts.