Why do changes in demand or supply cause disequilibrium?

Changes in demand or supply cause disequilibrium because they disrupt the balance between the quantity of goods consumers want to buy and the quantity producers are willing to sell at a given price. For example, an increase in demand can lead to a shortage if supply remains constant, resulting in upward pressure on prices. Conversely, a decrease in supply can create a surplus if demand stays the same, leading to downward pressure on prices. These imbalances prompt market adjustments until a new equilibrium is achieved.