Symptoms of low functioning autism, also classified as level 3 autism, are characterized by profound challenges in communication, social interaction, and daily behavior that require substantial support. Key symptoms include:

Communication and Social Challenges

• Limited or no verbal abilities, often relying on nonverbal cues, gestures, or alternative communication systems.
• Severe social withdrawal, including minimal eye contact and little to no interest in reciprocal interaction or peers.
• Difficulty understanding the emotions of others.

Behavioral and Sensory Traits

• Intense repetitive behaviors, such as hand-flapping or rigidly lining up toys, which can cause distress if disrupted.
• Extreme sensory sensitivities, where overreactions to specific sounds, textures, or household appliances (like vacuum cleaners) may lead to meltdowns.
• A strong need for predictability and difficulty navigating transitions or changes in routine.

Adaptive and Daily Living Skills

• Minimal self-care abilities, requiring full assistance with basic tasks like eating, dressing, or toileting.
• Significant impairments in adaptive functioning that limit personal autonomy and independence.

Early signs, such as delayed speech or minimal eye contact, typically emerge between 12 and 18 months and are often clearly observable by age two.