Arithmomania

Arithmomania, from the Greek arithmos, number, and mania, compulsion, is a mental disorder generally understood as an expression of obsessive-compulsive disorder. People affected by arithmomania experience a strong, often distressing need to count their own actions or the objects around them. This can take the form of compulsively counting footsteps while walking, letters within words, floor or ceiling tiles, or the painted lines along a highway, and sufferers frequently feel compelled to repeat an action a specific number of times before they can move on, such as switching a light on and off, or touching an object, until a particular count feels complete. As with other obsessive-compulsive presentations, failing to complete the count can provoke significant anxiety, while completing it brings only brief relief before the compulsion recurs, and the counting itself offers no practical benefit.