The Spoon Theory is a popular metaphor created by Christine Miserandino in 2003 to explain the daily reality of living with a hidden disability or chronic illness. It uses "spoons" as a unit of energy, with a person starting each day with a limited number of spoons. Every daily task—like showering, dressing, or working—costs a specific number of spoons. Once a person runs out of spoons, they have no energy left and must rest.

Because many disabilities and health conditions (such as lupus, fibromyalgia, autism, and chronic fatigue) are not immediately visible to others, this theory helps outsiders visualize the hidden mental and physical exertion required to navigate daily life. People with these conditions are often referred to as "spoonies"

Many people in the chronic illness and disability communities rely on this concept to set boundaries and explain their limits to friends and family. 

“On a high-pain day, a relatively simple task of showering or getting ready for the day can take four spoons. On a low-pain day, that same task might take just one spoon.