Early infancy repetitive behavioural patterns and social communication issues are hallmarks of autism spectrum disorder (ASD). Numerous genetic, environmental, and immunological variables are thought to have a role in the pathogenesis of ASD, but its etiology has remained a mystery in spite of intensive research. This review tries to clarify the main causes of ASD and investigate the most recent developments in its care. ASD pathogenesis has been linked to a number of genes related to synaptogenesis in neurons. Additionally, environmental elements and ailments like immunological imbalances and gastrointestinal (GI) abnormalities have been connected to the pathogenesis of ASD. Despite the fact that ASD has a solid hereditary foundation, various factors may either directly advance the disease or act as modifiers, aggravating its symptoms. Given the strong relationship between the immune system and the GI tract, abnormal immunological responses seen in autistic children may be caused by autoimmune diseases or infections in the mother. Furthermore, ASD has frequently been linked to mitochondrial malfunction, a common metabolic condition. It is thought that oxidative stress, a characteristic of many neurological illnesses, contributes to the development or occurrence of autism and autonomic dysfunction. Drug therapy have been shown to be inefficient in treating the primary symptoms of ASD, hence non-drug methods should be given priority first when it comes to treatment. But treating comorbidities and related symptoms like irritability and aggression may be helped by drugs.