Schizophrenia is a severe mental illness characterized by a disconnection from reality, significantly impacting a person's ability to function and leading to substantial disability. While the exact causes of schizophrenia remain unclear, it is understood to result from a combination of genetic, neurochemical, and environmental factors. The heritability of schizophrenia is high, although it does not follow Mendelian patterns. The symptomatology includes both positive symptoms such as hallucinations, delusions, and psychotic episodes, and negative symptoms like apathy and speech difficulties, which fluctuate in severity over time. Environmental influences, including prenatal and perinatal factors, trauma, and lifestyle, also play a crucial role in its development. The prevalence of schizophrenia is approximately 12.1% globally, with incidence rates higher in males than females. Genetic studies have identified several associations that contribute to the disease's pathophysiology, including common variants and copy number variants. Epigenetic mechanisms, such as DNA methylation and histone modifications, further influence gene expression and disease manifestation. The interplay between genetic predisposition and environmental factors underscores the complexity of schizophrenia and the importance of a multifaceted approach to its study and treatment.