Mental Health Act Sections: 2, 3, 5, 117 and 136 Explained

The sections you are most likely to hear about, with how long each one lasts:

Section 2 lets a hospital detain you for assessment, or assessment followed by treatment, for a period not exceeding 28 days. The application rests on written recommendations from two doctors, who must say you have a mental disorder of a nature or degree that warrants detention, and that you ought to be detained for your own health or safety or to protect other people.

Section 3 lets a hospital detain you for treatment. It also needs written recommendations from two doctors, but the test is different: the treatment must be necessary for your health or safety or to protect other people, it must not be possible to give it unless you are detained, and appropriate medical treatment must be available for you.

You could be detained for up to 6 months, with further renewals. During that time the doctor in charge of your care regularly assesses whether it is safe to discharge you.

These are the short emergency powers. Section 4 applies in a case of urgent necessity, when following the section 2 process would involve undesirable delay. It needs only one medical recommendation, and it ends after 72 hours unless a second recommendation is received.

Sections 5(2) and 5(4) apply if you are already in hospital. Section 5(4) gives certain nurses the power to detain you for up to 6 hours until a doctor can decide. Section 5(2) gives doctors the power to detain you for up to 72 hours, during which you should get an assessment of whether further detention is necessary.

These let the police take someone to a place of safety for assessment. Under section 135, a magistrate can issue a warrant letting the police enter premises, by force if necessary. Under section 136, the police can act without a warrant if you appear to have a mental disorder and to need immediate care or control.

Section 136 cannot be used in a house, flat or room where you or anyone else is living, or in its garden or garage. Before using it, an officer must, if practicable, consult a doctor, a nurse or an approved mental health professional. You can be kept at the place of safety until the assessment is completed, for up to 24 hours, extended to 36 hours if it was not possible to assess you in that time.

A place of safety is usually a hospital, but may be a police station if necessary in an emergency. A child, meaning anyone under 18, may not be taken to a police station as a place of safety.

Section 117 is a duty on the NHS and your council to provide aftercare when you leave hospital. It applies if you were detained under section 3, or under certain court or transfer orders (sections 37, 45A, 47 and 48). Being on section 2 alone does not bring you within it. The duty lasts until both bodies are satisfied you no longer need the services.

The statutory guidance on the Care Act says a local authority must not charge for aftercare services under section 117. Our guide to care needs assessments explains how other care is assessed and charged.

You can appeal to the Mental Health Tribunal or to the hospital's managers. The tribunal is independent and decides whether you should be discharged. You can apply yourself, or ask someone else to apply for you, such as a legal representative or family member.

If you do not apply under section 3, you will be referred to the tribunal automatically in the second 6 months. Download the form, say what you are applying for and send it by email or post. You can apply for legal aid to cover legal help if you made the application, and our legal aid guide explains how it works.

You usually get the decision on the day and full written reasons within 7 days. The tribunal can order your discharge, on the same day or at a future date, but it cannot change your treatment, such as medication.

• The hospital must take practicable steps to make sure you understand which section you are on, what it means and your right to apply to a tribunal, both orally and in writing.
• You have the right to see an independent mental health advocate, who can help you understand your rights.
• Your family keeps the right to visit, though you can refuse visitors and hospital staff will respect that.
• Your responsible clinician can authorise leave from hospital under section 17, and can place conditions on it.
• You may be treated against your will in certain circumstances. A second opinion appointed doctor checks some treatment when you refuse it or are too ill to consent.
• You can complain to the Care Quality Commission if you are unhappy with how the Act has been used.

Your nearest relative can also order your discharge from section 2 or 3, after giving the hospital 72 hours' notice. Your responsible clinician can stop this with a report saying you would be likely to act in a manner dangerous to other people or yourself. Your nearest relative also has the right to ask the local approved mental health professional service for an assessment. If you are a carer, our guide to Carer's Allowance covers the money side.

The Mental Health Act 2025 became law on 18 December 2025, and the NHS says the changes will happen in stages over several years. Most of it starts on a day the government has yet to appoint. Among the provisions still to come are a new nominated person role, changes to the grounds for detention and to detention periods, advance choice documents, and the removal of police stations and prisons as places of safety.

One change is already in force. Since 6 April 2026, private care providers must act compatibly with the Convention rights in the Human Rights Act when providing the services the Act lists. Our Human Rights Act guide explains those rights.

Wales uses the same 1983 Act, but tribunal cases go to the Mental Health Review Tribunal for Wales, because the tribunal described above deals with cases in England.

Scotland has its own law, the Mental Health (Care and Treatment) (Scotland) Act 2003. An emergency detention certificate authorises detention in hospital for 72 hours. A short-term detention certificate authorises detention for 28 days.

Northern Ireland has the Mental Health (Northern Ireland) Order 1986. Assessment can last up to 7 days after a report from the responsible medical officer, and detention for treatment can last up to 6 months. Our rights guides cover your other legal rights.