Autism is a developmental disorder characterized by difficulties with social interaction and verbal exchange, and via restricted and repetitive behaviour. Parents often are aware symptoms at some point of the first three years of their toddler's lifestyles. Those signs often develop gradually, though a few children with autism experience worsening in their verbal exchange and social competencies after achieving developmental milestones at a ordinary pace. Autism is associated with a mixture of genetic and environmental factors. hazard factors at some point of being pregnant include sure infections, along with rubella, toxins such as valproic acid, alcohol, cocaine, pesticides, lead, and air pollution, fetal increase limit, and autoimmune diseases. Controversies surround different proposed environmental reasons; for example, the vaccine hypothesis, which has been disproven. Autism affects information processing inside the mind and how nerve cells and their synapses join and prepare; how this occurs isn't well understood. The Diagnostic and Statistical manual of intellectual disorders (DSM-5), combines autism and much less severe types of the condition, including Asperger syndrome and pervasive developmental disorder not in any other case special (PDD-NOS) into the diagnosis of autism spectrum disorder (ASD).