Let's see if we can figure out what's causing your developmental delay.
Select additional symptoms and we'll narrow your results.

What causes developmental delay? 16 possible conditions

Developmental Delay Overview

Children reach developmental milestones at their own pace. Minor, temporary delays are usually no cause for alarm. An ongoing delay or multiple delays in reaching milestones is called developmental delay. Developmental milestones include language, thinking, and motor skills.

Developmental delay may be caused by a variety of factors, including heredity, problems with pregnancy, and premature birth. The cause is not always known.

If you suspect your child has developmental delay, speak with your pediatrician. Developmental delay sometimes indicates an underlying condition. Only a doctor can diagnosis developmental delay. Early intervention may help your child's progress.

Causes of Developmental Delay

Although doctors can't always pinpoint the cause, a variety of things can contribute to developmental delay. Some conditions, like Down syndrome, for example, are genetic in origin. Infection or other problems during pregnancy and childbirth, as well as premature birth, can cause developmental delay.

Chronic ear infections in infancy and toddlerhood can cause hearing loss, leading to speech and language delay. According to the Environmental Protection Agency (EPA), developmental delay is also a symptom of lead poisoning in young children (EPA). 

Developmental delay can also be a symptom of other underlying medical conditions, including:

  • autism spectrum disorders
  • cerebral palsy
  • fetal alcohol spectrum disorders
  • Landau-Kleffner syndrome
  • myopathies, including muscular dystrophies

Speech and Language

According to the National Institute on Deafness and Other Communication Disorders (NIDCD), the most active time for learning speech and language is the first three years of life, as the brain develops and matures (NIDCD, 2010). 

The language learning process begins when an infant communicates hunger by crying. By the time they reach six months old, most can recognize the sounds of basic language. At 12-15 months, he or she should be able to say a few simple words, even if they are not clear. Most toddlers can understand a few words by the time they are 18 months old. When they reach three, most children can speak in brief sentences.

Speech Delay or Language Delay?

Speech and language delay are not the same. Speaking requires the muscle coordination of the vocal tract, tongue, lips, and jaw to make sounds. Speech delay is when your child stutters or has difficulty producing sounds the correct way. A disorder that makes it hard to put syllables together to form words is called apraxia of speech. 

Language disorder is when a child has a difficult time understanding what other people say, or cannot express his or her own thoughts. Language includes speaking, gesturing, signing, and writing.

Poor hearing can cause speech and language delay, so diagnosis usually includes a hearing test. Children with speech and language delay are often referred to a speech-language pathologist. Early intervention can be a big help.

Fine and Gross Motor Skill Delay

Fine motor skills include small movements like holding a toy or using a crayon. Gross motor skills require larger movements, like jumping, climbing stairs, or throwing a ball.

Children progress at different rates, but most children can lift their head by three months, sit up by six months, and walk well before their second birthday. By age five, most children can throw a ball overhand and ride a tricycle. 

Falling outside the normal range is not always cause for concern, but if your child is unable to perform tasks within the expected time frame, speak to your doctor. Motor skill delay may be caused by an underlying medical condition.

Autism Spectrum Disorders

Autism spectrum disorders (ASD) include a group of developmental disabilities in which the brain handles information in different ways. Classic autism usually includes language delay and intellectual disabilities.

Symptoms are sometimes obvious early on, but may not be noticed until a child reaches two or three years of age. Signs and symptoms of autism vary, but usually include delayed speech and language skills. Children with autism may have difficulty communicating and interacting with others.

There is currently no cure for autism, but early intervention and education can help your child progress.

If You Suspect Your Child is Developmentally Delayed

Remember that children develop at different rates. However, if you think your child is developmentally delayed, talk to your doctor. If your school-age child is diagnosed with developmental delay, you may be eligible for special services.

Specialized services vary according to need and local municipality. Check with your physician and your school district to find out what services are available. Specialized education, especially when started early, can help your child progress and achieve more in school.

Article Sources:

Read More

See a list of possible causes in order from the most common to the least.


Mental Retardation

Mental retardation or intellectual disability, (MR/ID), exists in children whose brains do not develop properly or function within the normal range. There are four levels of retardation: mild, moderate, severe, an...

Read more »


Cerebral Palsy

Cerebral palsy is a disorder of muscle movement and coordination caused by an injury to a child's brain that occurs before birth or during infancy. It affects the part of the brain that controls body movement. Othe...

Read more »


Down Syndrome

Down syndrome is the most common genetic condition in the United States. It causes physical and mental developmental delays and disabilities.

Read more »


Failure to Thrive

Your child may be diagnosed with failure to thrive if he or she falls below a healthy weight and shows signs of emotional underdevelopment. Typically, failure to thrive is discovered during a child's infant years. Idea...

Read more »


Muscular Dystrophies

Muscular dystrophies are a group of inherited diseases that damage and weaken your muscles over time. This damage and weakness is due to the lack of a protein.

Read more »


Hookworm Infections

Hookworms are parasites that affect the small intestine and lungs. The first sign of infection is usually a rash where the parasite entered the skin, followed by diarrhea.

Read more »



Hydrocephalus is a condition that occurs when fluid builds up in the skull and causes the brain to swell. The name literally means "water on the brain."

Read more »


The Truth Behind Clumsy Child Syndrome: Developmental Coordination Disorder

Children normally develop the ability to sit up, stand, walk, and talk at predictable ages. When they are late in achieving these milestones, it may be due to a developmental problem. Developmental Coordination Disorde...

Read more »


Cystic Fibrosis

Cystic fibrosis is a recessive genetic disorder that affects cells that produce mucous, sweat, and digestive juices. It may cause severe problems in the lungs, pancreas, liver, and intestine

Read more »


Fetal Alcohol Syndrome

Fetal alcohol syndrome (FAS) occurs when a baby is born with varied mental and physical defects due to the mother consuming alcohol during pregnancy.

Read more »



Homocystinuria is an inherited disorder that keeps the body from processing the essential amino acid methionine. Amino acids are the building blocks of protein. Methionine occurs naturally in various proteins. It i...

Read more »


Tuberous Sclerosis

Tuberous sclerosis (TS) is a rare genetic condition. Sometimes called tuberous sclerosis complex (TSC), the disorder causes noncancerous (benign) tumors to grow in the brain and other vital organs, and on the skin...

Read more »


All About Abetalipoproteinemia

Abetalipoproteinemia (ABL) is an inherited condition that prevents the body from completely absorbing certain dietary fats. Untreated, it can cause vitamin deficiencies that may have long-term effects on your health.

Read more »



Phenylketonuria is a rare genetic condition in which the body is unable to breakdown phenylalanine, an essential amino acid.

Read more »


Aase Syndrome

Aase syndrome is a rare, potentially genetic condition characterized by several birth defects. These include a reduced number of red blood cells from birth and three bones in one or both thumbs, instead of two.

Read more »



Adrenoleukodystrophy (ALD) refers to several different inherited conditions that affect the nervous system and adrenal glands. Other names for it are adrenomyeloneuropathy, childhood cerebral ALD, and Schilder-Addiso...

Read more »

This feature is for informational purposes only and should not be used to diagnose.
Please consult a healthcare professional if you have health concerns.