What is the criterion for hardship and difficulty that permits alleviation in Sharia?

The hardship that brings ease in Sharia (definition) is of two types: 1. Necessity (Dharurah): This is when a person reaches a point where, if they do not partake in what is forbidden, they will perish or be close to perishing. It is a state of extreme danger that permits committing what is unlawful or abandoning an obligation to avert harm. Examples include severe hunger that permits eating forbidden food, and coercion that permits uttering words of disbelief. 2. Need (Hajah (definition)): This is a state of hardship that does not lead to perishing but causes difficulty and strain. It is a lesser degree than necessity. An example is what necessitates expansion and removal of hardship.

The difference between them is that necessity is the fear for one's life from perishing, whereas need does not lead to perishing if unmet. Both permit taking a concession. Need (whether general or specific) is treated like necessity, thus influencing rulings and permitting what is otherwise forbidden.

The instances for concession in Sharia are sometimes known and specified, such as travel, illness, and coercion. Others are unspecified and vary depending on the person's situation and circumstances. In such a case, the person facing the affliction must consult a pious scholar for a fatwa (definition).