Developmental Delay

Every child grows and learns at their own speed. But there are certain skills — like sitting up, smiling, or waving — that most children learn around the same age. These are called developmental milestones. When a child takes longer than others their age to reach one or more milestones, it's called a developmental delay.

Children reach milestones at different times, but it's still important to monitor their development. If a child falls behind in one skill, it can cause delays in others.

Frequently Asked Questions (FAQ)

How common are developmental delays?

Developmental delays are very common, affecting at least one in six children.

What are the types of developmental delays?

• Physical: Difficulty using muscles to do tasks such as walking or using a spoon.
• Thinking and learning (Cognitive): Difficulty understanding or learning.
• Speech and language: Trouble speaking or understanding words.
• Social and emotional: Struggles expressing emotions or interacting with others.
• Daily living skills (Adaptive): Difficulty with everyday tasks like eating, bathing, or dressing.

How do I know if my child has a developmental delay?

Talk to your medical provider. They can screen your child's development and give you a milestone checklist. For children age three or younger, you can ask about Early Intervention (EI) services, which offer free evaluations. For children above three, talk to your local school district.

What services are available for children with developmental delays?

Your child could be eligible for free services through EI or your local school district. Help might include speech therapy, physical therapy, occupational therapy, behavior therapy, assistive technology devices, or counseling. Private services are also an option.

What causes developmental delays?

The cause of many developmental delays is unknown. But possible risk factors include:

• Genetics (family history)
• Exposure to drugs, alcohol, or toxins during pregnancy
• Premature birth
• Low birth weight
• Poor nutrition
• Trauma or stress
• Lack of oxygen at birth
• Infections or health conditions such as hearing loss or vision issues

What other conditions sometimes occur with developmental delays?

Children with developmental delays sometimes have an underlying condition such as autism spectrum disorder, cerebral palsy, or hearing loss.

What to Share with Your Medical Providers

When talking to medical providers, you might want to share:

• Details about anything you've noticed that concerns you, and when you first noticed it.
• Any unusual behavior — even small things such as unbalanced crawling or a lot of drooling are important to note.
• Videos of your child in different settings — at home, playground, library, etc.
• Any recent life changes — new sibling, illness, new foods, for example — can sometimes have an effect on development.

What You Can Do at Home

Getting help early makes a big difference. Here are some things you can do now:

• Create a fun and structured environment: Limit screen time, keep a regular routine, use visual schedules (pictures and charts to show what's coming next), and change up what toys you're actively using. Keeping daily life interesting but predictable is important.
• Play together: Spending time with your child is one of the best ways to help them learn and develop a range of skills. For example, peek-a-boo supports social and emotional growth. Playing with play dough strengthens hand muscles. Reading improves language and communication.
• Be patient and celebrate: Remember, each child develops at their own pace. Don't feel like every interaction needs to be a form of therapy and teaching. Playing, interacting, and finding joy in the little things is important for children and their parents and caregivers!

Learning about developmental delays and getting help is a journey. You're not alone.

Go Deeper

Find Resources

Milestones and Types of Developmental Problems

Therapies and Supports

About This Series

This series of handouts and web pages on health conditions was written by clinicians in Weill Cornell Medicine's Pediatric Mental Health Integration Program, partners in the ACT for Youth CYSHCN Program Center of Excellence at Cornell University.