Schizophrenia is a serious mental illness that affects about 70 million people worldwide. It is characterized by distortions in thinking, perception, emotions, language, sense of self and behavior. Common symptoms include hallucinations, delusions, reduced social engagement and emotional expression. While the exact causes are unknown, genetic and environmental factors likely contribute. Treatment involves antipsychotic medications and psychosocial therapies. With proper treatment, many people with schizophrenia can lead productive lives.