Types of Disabilities

Last Updated: 8/1/2022 6:01 PM


Autism Spectrum Disorders (ASDs) are a group of complex neurological developmental disabilities that are characterized by impaired social interaction, problems with non-verbal and verbal communication, and unusual or severely limited activities, interests, or behaviors. Other commonly occurring difficulties include unusual responses to everyday sensations such as sounds, touch or visual stimuli, etc., often accompanied by marked difficulty learning how to regulate and control behavioral responses. There are innumerable combinations of how the core deficits manifest themselves and there is no one single characteristic or behavior that is common to all students with Autism Spectrum Disorders.


Blind/Visual Impairment

Students with visual impairments are those students who are blind or have low vision. The regulatory definition of visual impairment is "... an impairment in vision that, even with correction, adversely affects a child's educational performance."  This ranges from students who are totally blind or with minimal light perception, to students with functional vision, although less than the norm. For some students, visual impairment is their only disability, while others have one or more additional disabilities that will affect, to varying degrees, their learning and development.

The effect of a visual impairment on a student's development depends on the severity, type of loss, age at which the condition appears, and overall functioning level of the student. Less than 1% of all students in Pennsylvania are visually impaired. Students with visual impairments have complex and unique educational needs, which often require highly specialized services, equipment, and materials.

Vision impairment creates a filter that affects the student's ability to receive and give information, as well as to interact. Since vision is the primary sense upon which most traditional education strategies are based, these strategies need to be modified to reflect the student's visual, auditory, and tactual capabilities. Understanding the functional and educational effects of the visual impairment is essential to adjusting education strategies, as well as to the instruction and assessment processes.



Deaf-blindness means concomitant hearing and visual impairments, the combination of which causes such severe communication and other developmental and educational needs that they cannot be accommodated in special education programs solely for children with deafness or children with blindness.


Emotional Disturbance

The Individuals with Disabilities Education Act (IDEA '97) defines emotional disturbance as

"A condition exhibiting one or more of the following characteristics over a long period of time and to a marked degree, and that adversely affects a student's educational performance:An inability to learn that cannot be explained by intellectual, sensory, or health factors An inability to build or maintain satisfactory interpersonal relationships with peers and teachers Inappropriate types of behavior or feelings under normal circumstances A general pervasive mood of unhappiness or depression A tendency to develop physical symptoms or fears associated with personal or school problems". The term includes schizophrenia. The term does not apply to students who are socially maladjusted, unless it is determined that they have an emotional disturbance. Students with emotional disturbances may struggle in school with reading, social skills, and self-management.


Intellectual Disability

Intellectual Disability means "significantly sub-average general intellectual functioning, existing concurrently with deficits in adaptive skills, that is manifested during the developmental period, and that adversely affects a student's educational performance." Adaptive skills that are assessed in the person's typical environment (e.g., school, home) and across all aspects of his or her life are those daily living skills needed to live, work, and play in the community. They include communication, self-care, home living, social skills, leisure, health and safety, self-direction, functional academics (reading, writing, basic math), community living, and work. A student with limits in intellectual functioning who does not have limits in adaptive skill areas may not be diagnosed as having intellectual disability.


Multiple Disabilities

Multiple disabilities means "concomitant impairments such as mental retardation plus blindness, mental retardation plus orthopedic impairment, etc., the combination of which creates educational needs that cannot be accommodated in special education programs solely for one of the impairments." The term does not include deaf-blindness.


Orthopedic Impairment

The Individuals with Disabilities Education Act (IDEA '97) defines Orthopedic Impairment as "a severe orthopedic impairment that adversely affects a child's educational performance. The term includes impairments caused by congenital anomaly (e.g., clubfoot, absence of some member, etc.), impairments caused by disease (e.g., poliomyelitis, bone tuberculosis, etc.), and impairments from other causes (e.g., cerebral palsy, amputations, and fractures or burns that cause contractures)."

Students with orthopedic impairments must follow the general education curriculum. However, some students may have an additional disability, or challenging medical interventions, that may require additional supports with learning to read, write, and do math.


Other Health Impairment

Other health impairments means "having limited strength, vitality or alertness including a heightened alertness to environmental stimuli that results in limited alertness in the educational environment, and that adversely affects a child's educational performance. This disability is typically due to chronic or acute health problems, such as asthma, attention deficit disorder or attention deficit hyperactivity disorder, diabetes, epilepsy, a heart condition, hemophilia, lead poisoning, leukemia, nephritis, rheumatic fever, and sickle cell anemia."

Students with other health impairments may struggle in school with reading, writing, and math. Because of health issues, the student may have sporadic or poor school attendance and may fatigue easily during the school day.


Specific Learning Disability

The Individuals with Disabilities Education Act (IDEA '97) defines Specific Learning Disability (SLD) as "a disorder in one or more of the basic psychological processes involved in understanding or in using language, spoken or written, that may manifest itself in an imperfect ability to listen, think, speak, read, write, spell, or to do mathematical calculations, including conditions such as perceptual disabilities, brain injury, minimal brain dysfunction, dyslexia, and developmental aphasia. The term does not include learning problems that are primarily the result of visual, hearing, or motor disabilities, of mental retardation, of emotional disturbance, or of environmental, cultural, or economic disadvantage."

A team may determine that a student has a specific learning disability if:

The student does not achieve commensurate with his or her age and ability levels in one or more of the areas listed below, when provided with learning experiences appropriate for the student's age and ability levels, and The team finds that a student has a severe discrepancy between achievement and intellectual ability in one or more of the following areas: Oral expression Listening comprehension Written expression Basic reading skill Reading comprehension Mathematics calculation Mathematics reasoning. The team may not identify a student as having a specific learning disability if the severe discrepancy between ability and achievement is primarily the result of:

A visual, hearing, or motor impairment, Intellectual Disability, Emotional Disturbance, Environmental, cultural or economic disadvantage.


Speech and Language Impairment

Speech or Language Impairment refers to a student's developmental or acquired difficulties in understanding or using speech and language, particularly as they relate to his or her participation and progress in school. Speech or language impairments are often evident in the following skill areas:

Articulation Voice Fluency or stuttering Comprehension and expression of language in oral, written, graphic and manual modalities in the areas of phonology, morphology, syntax, semantics and pragmatic aspects of communication Language processing, including pre-literacy and language-based literacy, including phonological awareness and sound segmenting and blending skills Cognitive aspects of communication, such as problems in memory and problem solving Establishing augmentative and alternative communication, including developing, selecting, and recommending such systems and devices.


Traumatic Brain Injury

The Individuals with Disabilities Education Act (IDEA '97) defines Traumatic Brain Injury (TBI) as "an acquired injury to the brain caused by an external physical force, resulting in total or partial functional disability or psychosocial impairment, or both, that adversely affects a child's educational performance. The term applies to open and closed head injuries resulting in impairments in one or more areas such as: cognition, language, memory, attention, reasoning, abstract thinking, judgment, problem-solving, sensory, perceptual, motor abilities, psychosocial behavior, physical functions, information processing, speech."

Students who have suffered a traumatic brain injury usually enroll in school after having had intense clinical intervention. The educational planning should start in the clinical environment and seamlessly continue through the entire support process to reintegrate the student into the local education setting. When the student returns to the local school, the curricular demands and instruction strategies must be identified and tailored to each specific student, depending on the type and severity of injury.


Visual Impairment

The Individuals with Disabilities Education Act (IDEA) officially defines the category as “an impairment in vision that, even with correction, adversely affects a child’s educational performance. The term includes both partial sight and blindness.”

College Guide for Students with Visual Impairments