Yes, there are four key measurements that doctors check during every well child visit. These are height (or length), weight, head circumference, and body mass index (BMI). These simple numbers tell your child’s doctor a lot about how your child is growing and if they’re healthy.

This guide will help you understand what each measurement means, why doctors check them, and what the results tell you about your child’s health and growth.

Why Growth Measurements Matter So Much

Think of growth measurements like a report card for your child’s body. Just like teachers track how well kids learn in school, doctors track how well children grow and develop.

Growth measurements help doctors spot problems early and make sure your child stays healthy. When doctors catch issues early, they can fix them before they become bigger problems.

These four measurements work together like pieces of a puzzle. Each one gives doctors important clues about your child’s health.

The 4 Essential Measurements Every Doctor Checks

Height and Length – How Tall Your Child Is Growing

For babies under 2 years old: Doctors measure length while your baby lies down with legs straight.

For children 2 years and older: Doctors measure height while your child stands up straight.

According to the American Academy of Pediatrics, in children birth to 36 months, we measure weight, height and head circumference. In children age 2 years and older, we look at height, weight and body mass index (BMI).

What Height Measurements Tell Doctors

Height shows if your child is growing as expected for their age. Doctors put this number on a growth chart to see how your child compares to other kids the same age and gender.

The growth chart uses percentiles. If your child is in the 50th percentile, it means they’re taller than 50% of kids their age and shorter than the other 50%. This is perfectly normal.

Red Flags Doctors Look For

• Your child dropping from one growth line to a much lower one
• No growth over several visits
• Growing much faster or slower than expected

Weight – Tracking Healthy Growth Patterns

Weight is one of the easiest measurements to take, but it tells doctors a lot about your child’s health.

How Doctors Measure Weight

The Centers for Disease Control and Prevention recommends using a digital scale and placing it on firm flooring (such as tile or wood) rather than on carpet. Babies get weighed on special baby scales, while older kids stand on regular scales.

What Weight Changes Mean

Steady weight gain: Shows your child is eating well and growing normally.

Slow weight gain: Might mean feeding problems or health issues.

Too fast weight gain: Could signal overeating or other health concerns.

Doctors don’t just look at one weight measurement. They track how your child’s weight changes over time and compare it to their height.

Head Circumference – Measuring Brain Growth

As explained by MedlinePlus, head circumference is a measurement of the head size taken by wrapping a measuring tape around the back of the head above the eyebrows.

This measurement is super important for babies and young children because it shows how their brain is growing.

When Doctors Check Head Size

• Birth to 36 months: Doctors measure head circumference at every visit
• After 3 years: Usually not needed unless there are concerns

What Head Circumference Shows

Your child’s head grows because their brain grows. If the head grows too fast or too slow, it might signal problems with brain development.

Normal Head Growth Patterns

• Newborns: Heads grow quickly in the first few months
• By age 2: Head growth slows down a lot
• After age 5: Very little head growth happens

The fontanel on the top of the head, which is diamond-shaped, closes by 2 years of age. This soft spot on babies’ heads helps their brain grow.

Body Mass Index (BMI) – Understanding Weight for Height

Beginning at age 2, a child’s body mass index (BMI) can be calculated. Height and weight are used to figure out the BMI.

BMI is different from just weight because it considers how tall your child is too. A tall child should weigh more than a short child of the same age.

How BMI Works for Kids

The CDC explains that BMI is used to assess a child’s physical growth. Because children and teens are growing, BMI values must be expressed relative to other children of the same sex and age.

Unlike adults, kids’ BMI changes as they grow. That’s why doctors use special charts that compare your child to other kids the same age and gender.

BMI Categories for Children

• Underweight: Below 5th percentile
• Normal weight: 5th to 85th percentile
• Overweight: 85th to 95th percentile
• Obese: 95th percentile and above

How Doctors Use Growth Charts

Growth charts are like maps that show if your child is on the right path for healthy growth.

Understanding Percentiles

Percentiles compare your child to 100 other kids the same age and gender:

• 25th percentile: Your child is smaller than 75 kids and bigger than 25 kids
• 50th percentile: Right in the middle – half are bigger, half are smaller
• 75th percentile: Your child is bigger than 75 kids and smaller than 25 kids

What Doctors Look For

The CDC notes that growth charts are not intended to be used as a sole diagnostic instrument. Instead, growth charts are tools that contribute to forming an overall health picture for the child being measured.

Doctors care more about your child following their own growth pattern than being in a specific percentile.

Age-Specific Measurement Guidelines

Newborn to 2 Years

During this time, babies grow incredibly fast. In the first year, infants should have well child exams at 3-5 days after birth, then at 1, 2, 4, 6, 9, and 12 months.

Key measurements:

• Length (lying down)
• Weight
• Head circumference

Ages 2-5 Years

Growth slows down but is still important to track. Children this age get checked once a year.

Key measurements:

• Height (standing up)
• Weight
• BMI (calculated from height and weight)
• Head circumference (if needed)

School Age and Beyond

After that, annual check-ups are sufficient through adolescence.

Key measurements:

• Height
• Weight
• BMI

What Abnormal Measurements Might Mean

When Doctors Get Concerned

When one of your child’s measurements stays below the 10th percentile or above the 90th percentile for their age, doctors pay extra attention.

But remember – being in the 10th or 90th percentile doesn’t automatically mean something is wrong. Some kids are just naturally smaller or bigger.

Growth Pattern Changes

Doctors worry more about sudden changes than specific numbers. For example, a provider may worry if a 6-month-old was in the 75th percentile, but then moved to the 25th percentile at 9 months, and dropped even lower at 12 months.

Common Reasons for Measurement Concerns

Slow growth might indicate:

• Not getting enough nutrition
• Chronic illness
• Hormone problems
• Genetic conditions

Too-fast growth might suggest:

• Overeating
• Hormone issues
• Other medical conditions

Tips for Accurate Measurements at Home

Measuring Height at Home

• Use a flat wall without molding
• Remove shoes and thick clothing
• Make sure your child stands straight
• Use a ruler or book on top of their head
• Mark the wall and measure from the floor

Tracking Weight Changes

• Use the same scale each time
• Weigh your child at the same time of day
• Remove heavy clothing
• Keep a simple log of measurements

What Parents Should Know About Growth Patterns

Every Child Grows Differently

Some children are naturally petite, while others are naturally bigger. What matters most is that your child follows their own growth curve consistently.

Growth Spurts Are Normal

A different growth pattern doesn’t necessarily signal a problem. It could simply be due to a growth spurt.

Kids often grow in spurts rather than steadily. They might grow a lot in a few months, then slow down for a while.

When to Ask Questions

Don’t hesitate to ask your doctor about:

• Sudden changes in your child’s growth pattern
• Concerns about your child being too small or too big
• Questions about nutrition and healthy eating
• Worries about your child’s development

Supporting Healthy Growth at Home

Nutrition Basics

Cessation of breastfeeding before six months and introduction of solid foods before six months are associated with childhood obesity and are not recommended.

For babies:

• Breastfeed for at least 6 months if possible
• Wait until 6 months to start solid foods
• Avoid juice before age 1

For toddlers and kids:

• Limit juice to 4-6 ounces per day
• Avoid sugary drinks
• Focus on whole foods, fruits, and vegetables

Physical Activity

The AAFP and AAP recommend that children participate in at least 60 minutes of active free play per day.

Active play helps children:

• Build strong bones and muscles
• Maintain healthy weight
• Develop coordination
• Sleep better

Preparing Your Child for Measurements

Making Visits Less Stressful

• Explain what will happen in simple terms
• Bring a favorite toy or comfort item
• Stay calm and positive
• Ask your child to help by standing still

What to Expect During Measurements

1. Weight first: Usually done right when you arrive
2. Height next: Standing against a wall or height measure
3. Head measurement: For younger children, using a soft tape measure
4. Recording results: Nurse or doctor writes everything down

Questions to Ask Your Doctor

About the Measurements

• “Is my child growing normally for their age?”
• “Should I be concerned about any of these numbers?”
• “How do these compare to past visits?”

About Supporting Growth

• “What can I do to support healthy growth?”
• “Are there any nutrition changes we should make?”
• “How much physical activity does my child need?”

When Measurements Lead to Additional Care

Sometimes, unusual measurements mean your child needs extra help or testing.

Common Follow-Up Steps

Nutrition counseling: If weight is too high or too low

Additional testing: Blood tests to check for underlying conditions

Specialist referrals: To pediatric endocrinologists or other specialists

More frequent visits: To monitor growth more closely

Remember, most children who need follow-up care do very well with proper support.

Final Thoughts

The four key measurements – height, weight, head circumference, and BMI – are simple but powerful tools that help doctors track your child’s health and development. While the numbers matter, what’s most important is that your child follows their own healthy growth pattern over time.

Regular well child exams in Vernon Hills give you and your doctor the chance to catch any concerns early and celebrate your child’s healthy growth. Remember that every child grows at their own pace, and these measurements are just one part of understanding your child’s overall health and wellbeing.

If you have concerns about your child’s growth or measurements, don’t hesitate to discuss them with your healthcare provider. They can help you understand what the numbers mean and create a plan to support your child’s healthiest growth.