The exact cause of learning disorders remains unknown. It is believed that disorders are most often caused by a malfunction in cognitive processing that affects receiving, processing and communicating information.

There are many potential causes of cognitive malfunctioning. These may include deficits in visual perception, language processes, ability to pay attention or memory. Various medical conditions can also cause learning disorders to develop. These include lead poisoning, fetal alcohol syndrome and fragile X syndrome (damage to the X chromosome that leads to mental retardation). Heredity also plays a role, as many patients with learning disabilities have family members with similar problems.

Perinatal injuries (such as in the months prior to or just after birth) are sometimes factors in learning disorders. In addition, women who use drugs and alcohol during pregnancy increase the risk of having children with learning disorders. Low birth weight, premature or prolonged labor and nutritional deficiencies are also associated with these disorders.

People of all ages, socioeconomic backgrounds and ethnic groups may develop learning disorders.