Intellectual disability, also referred to as mental retardation, is a disability that begins in childhood. People with intellectual disability have limitations in their mental functioning seen in below-average intelligence (IQ) tests and in their ability to communicate, socialize, and take care of their everyday needs. The degree of disability can vary greatly from person to person and be categorized as mild, moderate, severe, or profound.

Some cases of intellectual disability can be prevented with proper medical care. Children diagnosed with an intellectual disability are most successful when they get help early in life. If you suspect that your child may have an intellectual disability, contact your doctor.


Several hundred causes of intellectual disability have been discovered, but many are still unknown. The most common ones are:


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Risk Factors

A child could be at higher risk for intellectual disability due to any of the causes listed above, or due to mental retardation in other family members. If you are concerned that your child is at risk, tell your child's doctor.


Symptoms appear before a child reaches age 18 and vary depending on the degree of the intellectual disability. If you think your child has any of these symptoms, do not assume it is due to intellectual disability. These symptoms may be caused by other, less serious health conditions. If your child experiences any one of them, contact your pediatrician.

Symptoms include:

  • Learning and developing more slowly than other children the same age
  • Difficulty communicating or socializing with others
  • Lower than average scores on IQ tests
  • Trouble learning in school
  • Inability to do everyday things like getting dressed or using the bathroom without help
  • Difficulty hearing, seeing, walking, or talking
  • Inability to think logically

The following categories are often used to describe the level of intellectual disability, according to the American Family Physician:


  • IQ 50-70
  • Slower than normal in all areas
  • No unusual physical signs
  • Can acquire practical skills
  • Reading and math skills up to grades 3-6
  • Can conform socially
  • Can acquire daily task skills
  • Integrated in society


  • IQ 35-49
  • Noticeable delays, particularly speech
  • May have unusual physical signs
  • Can learn simple communication
  • Can learn elementary health and safety skills
  • Can participate in simple activities and self-care
  • Can perform supervised tasks
  • Can travel alone to familiar places


  • IQ 20-34
  • Significant delays in some areas; may walk late
  • Little or no communication skills, but some understanding of speech with some response
  • Can be taught daily routines and repetitive activities
  • May be trained in simple self-care
  • Need direction and supervision socially


  • IQ <20
  • Significant delays in all areas
  • Congenital abnormalities present
  • Need close supervision
  • Requires attendant care
  • May respond to regular physical and social activity
  • Not capable of self-care


Your doctor will ask about your child’s symptoms and medical history, and perform a physical exam. Standardized tests may be given that measure:

  • Intelligence—IQ tests measure a person’s ability to do things such as think abstractly, learn, and solve problems. A child may have intellectual disability if he has an IQ score of 70 or below.
  • Adaptive behavior—These are skills needed to function in everyday life, including:
    • Conceptual skills like reading and writing
    • Social skills like responsibility and self-esteem
    • Practical skills like the ability to eat, use the bathroom, and get dressed

Because children with mental retardation have a higher risk for other disabilities (such as hearing impairment]]> , visual problems, ]]>seizures]]> , ]]>attention deficit hyperactivity disorder]]> , or orthopaedic conditions), additional testing may be needed to check for other conditions.



Talk with your doctor about the best treatment plan for your child. Treatment is most helpful if it begins early in life. Treatment includes:

  • Family counseling
  • Human development training (eg, emotional skills, hand-eye coordination)
  • Special education programs
  • Life skills training (eg, preparing food, bathing)
  • Job coaching
  • Social opportunities
  • Housing services


To help reduce your child’s chance of becoming mentally retarded, take the following steps:

  • During pregnancy:
    • If you smoke, quit]]> .
    • Don’t drink alcohol or use drugs.
    • Eat a ]]>healthful diet]]> —one that is low in saturated fat and rich in whole grains, fruits, and vegetables.
    • Add extra ]]>folic acid]]> to your diet.
    • See your doctor regularly.
  • After birth:
    • Have your newborn screened for conditions that may produce mental retardation.
    • Have your child properly ]]>immunized]]> .
    • Schedule regular visits to the pediatrician.
    • Use child safety seats and bicycle helmets.
    • Remove lead-based paint from your home.
    • Keep poisonous household products out of reach .
    • Avoid ]]>aspirin]]> use. Aspirin is not recommended for children with a current or recent viral infection. Check with your doctor before giving a child aspirin.