What Are the Causes of Intellectual Disability?

Intellectual disability is a condition characterized by decreased mental, social and communication functioning or skills in an individual. A person with an intellectual disability will have trouble learning, taking care of himself and will generally develop slower than one without an intellectual disability. Several factors will cause an intellectual disability.

Delivery Problems

• Certain problems at birth or during labor will cause an intellectual disability; these include temporary oxygen deprivation, premature births, low birth weights and birth injuries.

Genetic Conditions

• Genetic conditions are the result of genetic abnormalities inherited from a person's parents, overexposure to x-radiation and disorders caused by infections during a pregnancy. Oftentimes, the combined genetics of two people will form certain disorders of the genes in their children. Some genetic disorders cause intellectual disabilities. Defective or missing enzymes cause disorders such as phenylketonuria. A person with a chromosomal disorder, too few or too many chromosomes, may also develop an intellectual disability such as Down's syndrome.

Health Problems

• In some cases, children who experience certain health problems after birth may develop intellectual disabilities. Diseases such as the measles, meningitis, chicken pox, encephalitis and whooping cough can damage the brain and cause the development of an intellectual disability. Other causes after birth include exposure to environmental toxins, such as mercury, or lead poisoning, near drowning or a blow to the head.

Pregnancy Problems

• In some cases, a problem during the pregnancy will prevent the development of a baby while in the womb and cause an intellectual disability. A common cause of preventable intellectual disability is the abuse of alcohol and drugs by the pregnant mother. Other causes of pregnancy problems are infections such as rubella, environmental toxins, malnutrition and illnesses during the pregnancy such as toxoplasmosis a parasitic disease, cytomegalovirus, a common virus and syphilis.

Social Factors

• Impoverished children are often exposed to several factors that increase the risk of developing an intellectual disability. Oftentimes, children in these types of situations may not receive adequate health care, experience extreme malnutrition and live near environmental health hazards. In some cases, under-stimulation of the brain during the early educational years also increases the risk of developing an intellectual disability.