Hyperactivity is an effect that can occur for many people either while living sober or under the influence of certain psychoactive substances like stimulants. This can be described as feeling overly or extremely active or "speedy" and can often result in the inability to stay still or keep a clear and steady thought flow. It can manifest itself for many reasons ranging from general anxiety, severe apprehension, euphoria to just feeling over-stimulated both mentally and physically. The hyperactive effect itself can range from mild to extreme depending on several factors such as the substance being used, dosage, mindset and tolerance of the individual. It can be accompanied by a variety of related physical effects such as constantly moving or fidgeting and feeling a sense of urgency to do something. This most often results in the user being partially to entirely unable to focus on one thing at a time.