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Intellectual Disabilities


The Manual's Editorial Staff

Last full review/revision Oct 2019| Content last modified Oct 2019
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What is intellectual disability?

Intellectual disability is a brain problem that results in lower than normal intelligence. It can happen as your baby's brain develops in your womb. The disability can be mild or more severe, but people usually need some help carrying out daily activities and caring for themselves.

  • Children with intellectual disability may have physical differences, such as unusual facial features

  • Most children start to show symptoms in preschool—they are usually slower to speak and use sentences

  • Treatment includes different kinds of therapy and special education

To lower the chance of your baby having intellectual disability:

  • Take folate (folic acid) before conception and in early pregnancy

  • Avoid alcohol during pregnancy

  • Get good prenatal care

  • Get all needed vaccinations, especially against rubella

What causes intellectual disability?

Intellectual disability has many causes. Most of the time, something happens that affects your baby's developing brain before birth. This can include:

  • Chromosomal problems such as Down syndrome

  • Inherited disorders such as Tay-Sachs disease

  • Certain kinds of infection during pregnancy

  • Severe malnutrition during pregnancy

  • Use of alcohol, certain drugs, or certain medicine during pregnancy

Sometimes, intellectual disability happens because of problems during birth, such as:

  • Not enough oxygen during birth

  • Being born very prematurely

Sometimes, intellectual disability develops after birth. Causes include:

  • Head injury

  • Brain infection

  • Emotional abuse and neglect

  • Brain tumor

What are the symptoms of intellectual disability?

Some children show differences at birth or shortly after birth, such as:

  • Unusual facial features or a head that’s unusually large or small

  • Unusually shaped hands or feet

Sometimes children may have signs of a health problem, such as:

  • Seizures, weakness, and tiredness, or throwing up

  • Urine that has an unusual odor or smells

  • Failure to eat and grow normally

  • Delays in learning to roll over, sit up, and stand

You may not notice symptoms until your child starts school and you see your child in comparison to other children the same age. Your child may have:

  • Language problems, such as a later start using words or speaking in full sentences

  • Trouble making friends and other social skills

  • Trouble dressing and doing other self-care tasks

  • Sometimes, behavior problems such as temper tantrums or aggression, especially if frustrated

  • In older children, being gullible and letting other children take advantage

  • Sometimes, a mental health disorder such as anxiety or depression, especially if the child gets picked on or is aware of being different

How can doctors tell if my child has intellectual disability?

As part of your child's regular checkups, doctors will ask questions to check that your child is developing as expected. If doctors suspect an intellectual disability, they’ll send your child for:

  • Intelligence tests

  • Tests of speaking, social, and motor skills

If your child has intellectual disability, doctors will try to find out what's causing it. Doctors may do:

  • Genetic testing called chromosomal microarray

  • Urine and blood tests

  • Bone x-rays

  • Imaging tests of the brain, such as MRI and electroencephalogram (EEG)

How do doctors treat intellectual disability?

Treatment is based on your child's needs and strengths. Children may work with a team of health and school professionals, including:

  • Primary care doctor (such as a pediatrician)

  • Social workers and psychologists for counseling

  • Speech, occupational, and physical therapists to help them learn to do daily activities

  • Specialty doctors for brain and nerve problems

  • Nutritionists to help with healthy eating

  • Special education teachers

In the United States, the federal Individuals with Disabilities Education Act (IDEA) requires public schools to test children for intellectual disability. It also requires schools to provide free and appropriate education to children with intellectual disability.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
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