In emergencies:
An emergency is when someone seems to be at serious risk of harming themselves or others. Police have power to enter your home if they need by force under a section 135 warrant.
You may be taken to a place of safety for an assessment by an approved mental health professional and a doctor. You can be kept there until the assessment is complete, up to 24 hours which can be extended to 36. Find out more about the Section 135 warrant on the GOV.UK website.
If police find you in a public place and you appear to have a mental health disorder and need immediate care or control, they can take you to a place of safety and detain you under Section 136. Find out more about the Section 136 warrant on the GOV.UK website.
If you're already in hospital, certain nurses can stop you leaving under Section 5(4) until the doctor in charge of your care or treatment, or their nominated deputy, can decide about whether to detain you there under Section 5(2).
Non-emergencies:
In most non-emergency cases, family members, a GP, carer, or other professionals may voice concerns about your mental health. They should discuss this with you, and together you should decide about what help you may need, such as making an appointment with your GP to discuss further options.
But there may be times when there are sufficient concerns about your mental health and your ability to make use of the help offered. In these circumstances your relatives or the professionals involved in your care can ask for a formal assessment of your mental health through the Mental Health Act process
Your nearest relative has the right to ask the local approved mental health professional service, which may be run by local social care services, for an assessment under the Mental Health Act
It's also possible for a court to consider using the Mental Health Act in some circumstances, or for a transfer to a hospital to take place from prison. As part of this formal process, you'll be assessed by doctors and an approved mental health professional. One of the doctors must be specially certified as having experience in the assessment or treatment of mental illness.
Find out more about getting a mental health assessment