A “nervous breakdown” (or “mental breakdown”) is a term used to describe a period of intense mental distress that occurs progressively or suddenly. During this period, you’re temporarily unable to function in your everyday life. “Nervous breakdown” is not a medical term or a mental health diagnosis, since it does not describe a specific condition. It doesn’t have one agreed-upon definition but is instead used by many people to describe intense symptoms of stress and an inability to cope with life’s challenges. The signs of a nervous breakdown vary from person to person. The underlying cause can also affect the types of symptoms you experience. Here are some common signs of a nervous breakdown that can help you evaluate what you or a loved one is experiencing: