In a medical emergency, the patient may be obviously incapable of making a decision because they are unconscious and treatment cannot be put off.
People who experience delirium or altered states of consciousness, such as during a urinary tract infection, can temporarily lose capacity.
Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be as effectively achieved in a way that is less restrictive of the person's rights and freedom of action.
A mental capacity assessment should take place when there is an impairment of, or disturbance in the functioning of a person's mind or brain and a decision that needs to be made.
[3] A mental capacity assessment in respect of a lower-level day-to-day decision may be made by a carer or relative and need not be formally recorded, but capacity assessments about decisions that are complex or have important ramifications for the person are made by social workers, doctors or multi-disciplinary teams on behalf of local authorities and clinical commissioning groups, who have a lead role in implementing the Mental Capacity Act and are required to keep formal records.
Best interest decisions should promote the person's welfare while respecting their rights, their wishes and feelings, and their freedom.
The law assumes that carers and relatives will be able to make lower-level, day-to-day best interest decisions for a person lacking capacity.
Generally speaking, a decision would need to involve a social worker or doctor if there is potential disagreement about capacity or what is in the person's best interest, if potentially life-affecting medical treatment is being considered, if abuse or crime is suspected, if significant amounts of money are involved, or if other people might be at risk.
The authorities are all agreed that the starting point is a strong presumption that it is in a person's best interests to stay alive.
As Sir Thomas Bingham MR said in the Court of Appeal in Bland, at p 808, "A profound respect for the sanctity of human life is embedded in our law and our moral philosophy".
An ordinary power of attorney is made by a person who is capacitous, and only lasts while they continue to have capacity.
[11] Someone with lasting power of attorney for health and welfare can make decisions about where the donor should live (e.g. in their own home or in a care home of the attorney's choice), what medical care the donor should receive, what activities they should take part in, and with which people they can have social contact.
[13] A police constable also has powers to remove children from their parents without a Court Order for up to 72 hours.
[14] As a matter of Law the parental right to determine whether or not their minor child below the age of sixteen will have medical treatment terminates if and when the child achieves sufficient understanding and intelligence to understand fully what is proposed.The Fraser guidelines come from Lord Fraser's remarks in the same case.