In practice, patients need to be able to communicate their decision. Care should be taken not to underestimate the ability of a patient to communicate, whatever their condition. Health professionals should take all steps which are reasonable in the circumstances to facilitate communication with the patient, using interpreters or communication aids as appropriate. A health professional cannot decide that someone lacks capacity just by a person's age, appearance, condition or an aspect of their behaviour that might lead to unjustified assumptions about capacity. Where a health professional believes there is a question over the patients' capacity to consent to treatment they must have regard to the law that applies to capacity. The Mental Capacity Act 2005 brought together common law and other existing legal requirements to provide consistency in decision-making about the care and treatment of people who lack capacity to make a decision.