📏🌱 Why Is My Child Not Growing?

A practical, parent-friendly guide to poor growth (newborn → teen)

Parents often worry: “My child is not growing.” Growth is one of the best overall indicators of health—but not all “small” children have a medical problem.

This guide explains:

• When growth patterns are normal
• When growth is concerning
• Common causes (especially nutrition and gut-related causes)
• What evaluation usually includes
• What you can do today at home

🧾 Quick “At-a-glance” box

✅ Topic: Poor growth / poor weight gain / short stature
Common parent terms: “Not gaining weight,” “fell off the curve,” “small for age,” “not growing taller,” “picky eater,” “thin,” “short”

What it is (2–3 lines): Doctors focus on growth over time—not a single measurement. Many children are naturally small (family pattern or “late bloomer”), but growth becomes concerning when a child drops percentiles, has poor weight gain, slows height growth, or has symptoms suggesting chronic illness.

Who it affects (typical ages): Any age. The causes and urgency differ in infants vs older children vs teens.

✅ What parents should do today:

• Find your child’s growth measurements over time (height, weight).
• Check if they are following their curve or dropping percentiles.
• Keep a 3-day food and drink diary.
• Check for symptoms (diarrhea, vomiting, belly pain, fatigue, poor appetite).

⚠️ Red flags that need urgent / prompt medical review:

• Rapid drop in weight or height percentiles (“falling off the curve”)
• Severe weight loss or signs of dehydration
• Persistent vomiting, chronic diarrhea, blood in stool
• Very low energy, pallor, frequent fevers, or child looks unwell
• Severe abdominal pain or poor appetite lasting weeks
• Breathing trouble, severe headaches, or new neurologic symptoms
• Delayed puberty well beyond expected timing

🟡 When to see the family doctor/clinic soon:

• Weight gain is slow for weeks to months
• Height growth seems slower than expected
• Persistent picky eating with low intake
• Recurrent belly symptoms (pain, nausea, constipation, diarrhea)
• Ongoing fatigue or school performance decline

🧠 What it is (plain language)

“Not growing” can mean:

• Not gaining weight well (poor weight gain)
• Not growing taller well (slow height growth)
• Both

Doctors pay close attention to:

• The pattern over time
• Whether the child is following their curve
• Whether they are dropping percentiles
• Family growth pattern and puberty timing

What part of the body is involved? (small diagram required)

Common myths vs facts

• Myth: “If my child is small, something must be wrong.”
  Fact: Many healthy children are small due to genetics or being “late bloomers.”
• Myth: “One low measurement proves there’s a growth problem.”
  Fact: A single number is less important than the trend over time.
• Myth: “If my child eats little, they’ll grow out of it.”
  Fact: Some kids do—but persistent low intake can affect growth and needs a plan.

🧩 Why it happens (causes & triggers)

Growth problems usually fall into a few big buckets. A child can have more than one.

1) Not enough calories (most common overall)

This can happen when:

• The child eats small amounts (picky eating, sensory feeding issues)
• They graze all day but don’t eat full meals
• They drink too much milk/juice and feel full
• Meals become stressful (pressure and battles reduce intake)
• Eating is uncomfortable (reflux irritation, swallowing discomfort)

2) Poor absorption (malabsorption)

Examples:

• Celiac disease
• Chronic diarrhea disorders
• Pancreatic problems (less common)

Clues:

• Chronic diarrhea
• Bulky, greasy, foul-smelling stools
• Bloating
• Poor weight gain despite decent appetite

3) Chronic inflammation or chronic disease

Examples:

• Inflammatory bowel disease (IBD)
• Kidney disease, heart disease
• Chronic infections

Clues:

• Fatigue, anemia
• Chronic belly pain
• Diarrhea or blood in stool
• Frequent fevers or “always unwell”
• Poor appetite, weight loss

4) Hormonal/endocrine causes (often affect height more than weight)

Examples:

• Hypothyroidism
• Growth hormone deficiency

Clues:

• Height growth slows more than weight
• Child looks proportionally “younger” than peers
• Sometimes delayed puberty

5) Genetics and normal variants

• Familial short stature (healthy and short like parents)
• Constitutional delay (“late bloomer”: later puberty and catch-up)

6) Feeding/swallowing discomfort (can reduce intake)

If eating causes discomfort, children may eat less. Possible clues:

• Eats very slowly
• Avoids meats/breads
• Needs water to “wash food down”
• Recurrent vomiting or “food stuck” episodes
• History of allergy conditions (eczema/asthma) sometimes co-exists with conditions like EoE

👀 What parents might notice (symptoms)

Typical signs that suggest “just small” vs “concerning”

✅ Often reassuring patterns:

• Child is growing steadily along a similar curve
• Energy is good, development is normal
• No chronic GI symptoms
• Family members are also small or late bloomers

⚠️ More concerning patterns:

• Dropping weight percentiles (or height percentiles)
• Appetite is very low for weeks
• Persistent vomiting, diarrhea, blood in stool
• Fatigue, pallor, fevers
• Belly pain affecting school or sleep
• Puberty seems very delayed

Symptoms by age group

Infants

• Poor weight gain is more urgent to address
• Feeding difficulties, vomiting, diarrhea, and decreased wet diapers matter a lot

Toddlers/preschoolers

• Picky eating is common—but persistent low intake and grazing can drive poor weight gain
• Constipation is common and can reduce appetite

School-age children

• Falling off the curve + belly symptoms raises suspicion for gut inflammation (including IBD) or malabsorption (including celiac)

Teens

• Puberty timing matters a lot (late puberty can look like “not growing”)
• Diet, stress, sleep, and chronic disease can all affect growth

Symptom trackers (what to write down)

• 3-day food/drink diary (include milk/juice amounts)
• Stool pattern (constipation vs diarrhea; blood/mucus)
• Vomiting or nausea
• Belly pain (location, frequency)
• Energy, sleep quality, school performance
• Puberty changes (growth spurt, body changes—when appropriate)

🏠 Home care and what helps (step-by-step)

✅ Do this now: You can do a lot at home while waiting for evaluation—especially for calorie intake and meal structure.

What to do in the first 24–48 hours

1. Get the growth data

• Write down: last 6–12 months of weights/heights if you can access them

2. Start a 3-day food + drink diary

• Include everything: snacks, milk, juice, supplements, “bites and sips”

3. Stop grazing

• Create predictable times for meals/snacks (structure increases intake)

4. Increase calories safely

• Add calorie boosters to foods your child already accepts (see below)

Practical routines that often help

Structure meals and snacks (simple plan)

• 3 meals + 2–3 planned snacks
• Water between meals
• Keep milk/juice amounts reasonable (too much can replace food)

Calorie boosting (healthy ways)

• Add olive oil/butter to rice/pasta/vegetables
• Add cheese to eggs, potatoes, casseroles
• Use yogurt, hummus, avocado
• Nut butters if age-appropriate and safe for allergies
• Choose higher-calorie versions of familiar foods (whole milk yogurt, etc.)

Treat constipation if present (appetite improves)

Constipation can cause:

• Nausea
• Reduced appetite
• Belly pain
  A constipation plan can improve eating in many children.

Avoid pressure and battles at meals

Pressure often backfires and reduces intake. Aim for:

• Calm routine
• Short meals (20–30 minutes)
• Praise effort and sitting, not “finishing”

⛔ What NOT to do (common mistakes)

• Don’t compare your child to other children (growth is individual)
• Don’t stop gluten before celiac testing if celiac is suspected
• Don’t rely on “more fiber” alone if constipation is significant
• Don’t start major diet restrictions without medical guidance (risk of worsening nutrition)
• Don’t assume it’s “behavior” if there are red flags or persistent GI symptoms

🚦 When to worry: triage guidance

🔴 Call 911 / Emergency now

• Severe weakness/collapse, very hard to wake
• Severe dehydration signs (very low urine + lethargy)
• Breathing difficulty

Example: “My child is extremely sleepy and barely peeing.”

🟠 Same-day urgent visit

• Rapid weight loss, dehydration, inability to keep fluids down
• Blood in stool with significant illness
• Severe persistent vomiting or severe abdominal pain
• Baby/young infant with poor feeding plus concerning symptoms
• Child looks very unwell (pale, weak, fevers)

Example: “They’ve lost weight quickly and can’t keep food or fluids down.”

🟡 Book a routine appointment (but don’t delay)

• Dropping percentiles over months
• Persistent low appetite, picky eating with low intake
• Chronic diarrhea or constipation
• Fatigue, pallor, school decline
• Concerns about delayed puberty

Example: “They used to be average weight, now they’re dropping on the chart.”

🟢 Watch at home (with tracking)

• Child is small but tracking their curve, energetic, and symptom-free
• Family pattern suggests genetics or late bloomer
• You’re still encouraged to discuss at the next routine visit

🩺 How doctors diagnose it (what to expect)

What the clinician will ask

• Birth history (prematurity, early feeding issues)
• Detailed diet review (including drinks)
• Stool patterns and GI symptoms
• Sleep, energy, infections, fevers
• Family heights and puberty timing
• Medications (some affect appetite)
• Psychosocial stress and meal dynamics

Physical exam basics

• Accurate measurements (good technique matters)
• Weight, height, BMI, and growth velocity
• Puberty staging (when appropriate)
• Signs of anemia, chronic inflammation, malnutrition
• Belly exam

Possible tests (and why)

Tests are chosen based on symptoms and exam. Common starting tests may include:

• Blood count and iron studies (anemia)
• Inflammation markers (if chronic disease suspected)
• Thyroid function
• Celiac screening
• Kidney/liver tests
• Stool tests if diarrhea is present

✅ Sometimes the single most helpful step is a dietitian assessment plus a structured feeding plan.

What tests are usually not needed

• Extensive testing in a child who is thriving, tracking their curve, and has no concerning symptoms

What results might mean (simple interpretation)

• Low intake: nutrition plan + routine often improves weight gain
• Malabsorption (like celiac): targeted treatment improves growth
• Inflammation (like IBD): specialist care can restore growth trajectory
• Endocrine issues: pediatric endocrinology evaluation and targeted therapy when indicated

🧰 Treatment options

First-line treatment (most common)

• Nutrition strategy (calorie boosting, meal structure)
• Treat constipation if present
• Address feeding skill or sensory issues (feeding therapy when needed)

If not improving (next steps)

• Targeted medical evaluation (GI, endocrine, or other depending on clues)
• Dietitian involvement
• Consider specialist referral if growth continues to fall or symptoms suggest chronic disease

Severe cases (hospital care)

• Dehydration, inability to maintain intake
• Rapid weight loss
• Severe systemic illness or significant GI bleeding

⏳ Expected course & prognosis

Typical timeline

• Nutrition-driven poor weight gain often improves over weeks to months once intake is consistently increased
• Height catch-up can take longer
• If there is an underlying medical cause (celiac, IBD, endocrine), growth often improves after treatment, but timing varies

What “getting better” looks like

• Better appetite and intake
• Weight stabilizes and begins to rise
• Energy improves
• Fewer GI symptoms
• Growth curve stops dropping and begins tracking again

What “getting worse” looks like

• Continued percentile drop
• New diarrhea, blood in stool, vomiting
• Fatigue, pallor, fevers
• Worsening belly pain
• School avoidance or low energy

Return to school/daycare/sports guidance

• Encourage normal activity if the child is well
• If fatigue is significant, prioritize evaluation and sleep/nutrition support

⚠️ Complications (brief but clear)

Common complications

• Low energy and irritability
• Micronutrient deficiencies (iron, vitamin D, etc.)
• Increased stress around meals

Rare serious complications (red-flag reminder)

• Severe malnutrition or dehydration
• Complications of chronic inflammatory disease

🛡️ Prevention and reducing future episodes

• Establish predictable meal/snack structure early
• Treat constipation proactively
• Avoid prolonged feeding battles
• Recheck growth regularly (so changes are caught early)
• Address chronic symptoms promptly (diarrhea, vomiting, blood in stool)

🌟 Special situations

Infants

• Poor weight gain is more urgent and needs closer follow-up
• Feeding assessment and hydration status are critical

Teens

• Puberty timing is a major factor in growth
• Late puberty can be normal (“late bloomer”) but needs assessment if very delayed
• Consider stress, sleep, and disordered eating patterns if intake is restricted (approach gently and privately)

Kids with chronic conditions

• Growth can be affected by inflammation, medications, and appetite
• Lower threshold for nutrition support and specialist input

Neurodevelopmental differences/autism

• Sensory feeding issues are common
• Feeding therapy and structured routines can be very effective
• Protect calories and micronutrients early

Travel considerations

• Keep routines and safe foods available
• Monitor intake and hydration
• Seek care if GI symptoms worsen

School/daycare notes

• Allow enough time to eat
• Encourage water access
• Avoid pressure-based “finish your lunch” expectations
• Communicate any medically advised dietary plans

📅 Follow-up plan

When to follow up and with whom

• Follow-up with your family doctor/pediatrician to review growth charts and symptoms
• Referral to dietitian, pediatric gastroenterology, or endocrinology depending on findings

What would trigger earlier follow-up

• Continued dropping percentiles
• New GI symptoms (diarrhea, blood, vomiting)
• fatigue, pallor, fevers
• worsening appetite or dehydration signs

What to bring to the appointment

• Growth records (if you have them)
• 3-day food and drink diary
• Stool diary (constipation/diarrhea/blood)
• Medication list
• Family heights and puberty timing (parents/siblings)

❓ Parent FAQs

“Is it contagious?”

No.

“Can my child eat ___?”

Usually yes. Most children need more calories, not fewer foods. Avoid major diet restrictions without guidance (and don’t stop gluten before celiac testing).

“Can they bathe/swim/exercise?”

Yes, as tolerated. If energy is very low, prioritize evaluation.

“Will they outgrow it?”

Some children are naturally small or late bloomers and do fine. But falling off the curve or chronic symptoms should be evaluated.

“When can we stop treatment?”

When growth stabilizes and your clinician confirms the curve is healthy again. Nutrition plans are often tapered gradually once intake and growth are reliable.

🧾 Printable tools

🧾 Printable: One-Page Growth Action Plan

Step 1: Check urgent red flags

• Rapid weight loss or dehydration
• Persistent vomiting or chronic diarrhea
• Blood in stool
• Severe abdominal pain
• Frequent fevers / child looks unwell
  ➡️ If checked: seek prompt medical care.

Step 2: Gather data

• Last 6–12 months of weight/height
• Family heights and puberty timing
• 3-day food + drink diary

Step 3: Start a home plan (safe steps)

• 3 meals + 2–3 planned snacks (no grazing)
• Calorie-boost accepted foods
• Treat constipation if present
• Keep meals calm (avoid pressure)

🧾 Printable: 3-Day Food & Drink Diary (Template)

Day 1 / Day 2 / Day 3

• Breakfast: __________________________
• Snack: _____________________________
• Lunch: _____________________________
• Snack: _____________________________
• Dinner: ____________________________
• Drinks (type + amount): ______________
• Notes (refusal, stress, vomiting, stool): _______________________

🧾 Printable: “Red flags” fridge sheet

⚠️ Urgent review if: falling off the curve quickly, severe weight loss/dehydration, persistent vomiting, chronic diarrhea, blood in stool, severe belly pain, frequent fevers, or child looks unwell.

🧾 Printable: School/Daycare Instructions Page

Supporting growth and intake

• Allow enough time to eat
• Encourage water access
• Avoid pressure-based “finish everything” rules
• Notify parents if lunch is consistently untouched or if child appears fatigued/unwell

🧡 Safety disclaimer

This guide supports—not replaces—medical advice. If you are worried about your child, trust your instincts and seek urgent medical assessment.

This guide was fully developed & reviewed by Dr. Mohammad Hussein, MD, FRCPC ROYAL COLLEGE–CERTIFIED PEDIATRICIAN & PEDIATRIC GASTROENTEROLOGIST
Board-certified pediatrician and pediatric gastroenterologist (Royal College of Physicians and Surgeons of Canada) with expertise in inflammatory bowel disease, eosinophilic gastrointestinal disorders, motility and functional testing, and complex nutrition across diverse international practice settings.
To book an online assessment Email Dr. Hussein’s Assistant Elizabeth Gray at: Elizabeth.Gray@pedsgimind.ca
In the email subject, please write: New Assessment Appointment with Dr. Hussein
Important: This appointment is completely online as Dr. Hussein is currently working overseas.
This service is not covered by OHIP