AAP failure to thrive: what families should know

It is a description of a growth pattern, not a single diagnosis. A clinician looks at measurements over time, feeding, development, medical history and family growth patterns before deciding what support or tests are appropriate.

Growth may slow when a child does not take in enough energy, has difficulty chewing or swallowing, loses nutrients through vomiting or diarrhoea, or has an illness that raises energy needs. Feeding routines, food access and parent-child feeding interactions also matter.

One measurement cannot show the full pattern. Weight, length or height, and head growth where relevant are plotted across visits. Clinicians also check hydration, muscle and fat stores, mouth and swallowing, development, and signs of an underlying condition.

Arrange a child health appointment and bring any growth records, a list of medicines, and a short feeding diary showing foods, drinks, meal timing, vomiting and stools. Follow the clinician's feeding plan; adding supplements or concentrating formula without guidance can create nutritional or mixing problems.

Offer calm, structured meals and snacks without force. Note whether the child tires, coughs or chokes during feeds, refuses particular textures, or has pain. These details help direct assessment and may indicate a need for feeding or swallowing support.

Seek urgent medical help if the child is unusually sleepy or difficult to wake, cannot keep fluids down, has trouble breathing, has green or bloody vomit, passes blood in the stool, or shows dehydration such as a very dry mouth or markedly reduced urination.

Prompt assessment is also warranted if feeding has suddenly deteriorated or weight appears to be falling. A young infant who is feeding poorly or seems unwell should be assessed without delay.

Ask how your child's measurements have changed over time, what daily feeding plan to follow, whether swallowing or developmental assessment is needed, and when growth should be checked again. Clarify which symptoms should trigger earlier review.