A patient may have an 'advance statement' or 'advance decision', sometimes referred to as a 'living will' or an 'advance directive', specifying how they would like to be treated in the event that they lose mental capacity in the future. An advance statement or decision cannot be ignored by health professionals. If treatment is given contrary to the advance decision the health professional may face civil liability or criminal prosecution. An advance decision to refuse treatment must indicate exactly what type of treatment the patient wishes to refuse and should give as much detail as necessary about the circumstances under which this refusal would apply. If an advance decision involves refusing life-sustaining treatment, it has to be put in writing, signed and witnessed. An adult with mental capacity can refuse treatment for any reason, even if this might lead to their death, as discussed ante.