Paranoia is a feeling of excessive or irrational distrust or suspicion of others, often accompanied by anxiety or fear. It can be a symptom of several mental health disorders, including schizophrenia, bipolar disorder, and depression. The severity of paranoia can range from mild distrust to severe delusions, where the individual believes that others are actively trying to harm them. The causes of paranoia are not fully understood but can include genetic factors, brain structure and function, drug use, and life experiences such as trauma or stress.

Treatment for paranoia typically involves therapy, medication, and lifestyle changes to manage symptoms and improve overall well-being. It is important to seek help from a mental health professional if you or someone you know is experiencing symptoms of paranoia.

Note: This is a general description. Please take professional health advice.