When someone you care for is sectioned, it can feel sudden, frightening and completely out of your control. It helps to know this is not something done to a person without limits; it is a legal process with strict rules, defined time limits and important rights attached. This guide explains what Section 2 and Section 3 of the Mental Health Act mean, in plain English.
Being “sectioned” means being detained in hospital under the Mental Health Act 1983 for assessment or treatment of a mental disorder, without your consent, when specific legal criteria are met. Section 2 is for assessment and lasts up to 28 days. Section 3 is for treatment and lasts up to 6 months at first, and can be renewed. In both cases, the person keeps clear rights including the right to appeal.
“Sectioning” is the everyday word for being detained under a section of the Mental Health Act 1983, the law that governs compulsory mental health care in England and Wales. It allows a person to be kept in hospital for assessment or treatment of a mental disorder even if they do not agree to it.
Detention is only lawful when set criteria are met, and it always involves more than one professional. A typical civil sectioning involves:
These health professionals must independently agree that the legal grounds are satisfied. The decision never rests on one person’s opinion alone. There must also be a genuine Mental Health Act assessment of the person’s mental state before they can be detained under Section 2 or Section 3.
Section 2 is used for assessment to understand what is happening and what care a person may need. Treatment can be given during this time, but the primary purpose is assessment.
A person can be detained under Section 2 when they are suffering from a mental disorder of a nature or degree that warrants assessment in hospital, and they ought to be so detained in the interests of their own health or safety, or for the protection of other people.
Because Section 2 ends after 28 days, one of three things usually happens before it runs out: the person is discharged, they agree to stay voluntarily, or they are moved onto Section 3 if longer treatment is needed.
Section 3 authorises detention in hospital for treatment. It is used when the mental disorder is already understood, and a clear treatment plan is in place.
Section 3 applies when a person has a mental disorder that makes treatment in hospital appropriate, it is necessary for their health or safety or for the protection of others, and appropriate medical treatment is available for them.
Section 3 also carries an important family safeguard. The nearest relative (a specific legal role, explained below) should normally be consulted and has the right to object. If the nearest relative objects, a Section 3 application usually cannot proceed unless a court removes them from that role. Being detained under Section 3 also entitles the person to free aftercare when they leave hospital, under section 117 of the Act.
The clearest way to compare section 2 and 3 of the Mental Health Act is side by side:
| Feature | Section 2 | Section 3 |
| Main purpose | Assessment (treatment possible) | Treatment |
| How long | Up to 28 days | Up to 6 months initially |
| Renewable? | No | Yes (6 months, then 12 months at a time) |
| Typical trigger | Condition unclear/first crisis | Diagnosis known / plan in place |
| Nearest relative can object? | No | Yes |
| Free section 117 aftercare? | No | Yes |
| Deadline to apply to the Tribunal | Within first 14 days | Once in the first 6 months |
The simplest way to remember it: Section 2 is short and about finding out; Section 3 is longer and about treating.
Section 2 and Section 3 are the two main civil sections, but you may hear others mentioned:
These are short-term measures with their own rules and time limits. They are not the same as being detained under Section 2 or Section 3.
This is the part that matters most, and it is often the most reassuring. Being detained under a section does not strip a person of their rights. Key protections include:
The Responsible Clinician, the senior clinician in overall charge of the person’s care, can also grant Section 17 leave (agreed time away from the ward), discharge the section, or, where appropriate, use a Community Treatment Order (CTO) so treatment can continue in the community rather than in hospital.
Takeaway: detention is time-limited, supervised, and reviewable and independent support is available from day one.
Families often feel shut out at the very moment they most want to help. The Act does give relatives a defined role.
The nearest relative is a specific legal position, not simply the closest family member emotionally, but the person identified by a set order in the Act (for example, husband, wife or civil partner, then eldest child, then parent, and so on).
The nearest relative can:
What families cannot do is override the clinical team or demand a particular treatment. But they can raise concerns, ask questions, request information, and get independent legal advice on the person’s behalf. If you are unhappy with how a detention is being handled, that concern is worth acting on early rather than waiting.
Yes. Being detained under a section is not the final word.
A detained person can apply to the Mental Health Tribunal, an independent panel including a judge, a doctor and a specialist member to review the detention and decide whether it should continue. In certain circumstances the nearest relative can also apply. The panel has the power to discharge the person from the section.
There are strict time limits for applying (for example, within the first 14 days for Section 2), so acting quickly matters. A specialist solicitor can prepare the case, gather evidence and represent the person at the hearing. Representation at a Mental Health Tribunal is covered by non-means-tested Legal Aid, meaning it does not depend on the person’s income or savings. You can read more on our Legal Aid page. Our Mental Health Solicitors team has significant experience with Mental Health Act detentions and Tribunal hearings, and can advise on whether an appeal is the right step.
It depends on the section. Section 2 lasts up to 28 days and cannot normally be renewed. Section 3 lasts up to 6 months at first and can be renewed. Short-term powers such as Section 4 or Section 136 last only hours.
Yes, that is what sectioning is: detention without consent. But it is only lawful when the legal criteria are met, the right professionals agree, and it is in the interests of the person’s health or safety, or for the protection of others.
Yes. A detained person can apply to the Mental Health Tribunal to be discharged, and a solicitor can represent them, usually under Legal Aid.
Section 2 is for assessment (up to 28 days, not renewable). Section 3 is for treatment (up to 6 months, renewable). Section 3 also gives the nearest relative a right to object.
An Approved Mental Health Professional usually makes the application, supported by two doctors. In an emergency involving the police in a public place, Section 136 may be used first.
No. Being detained under the Mental Health Act is a health matter, not a criminal one. A solicitor or IMHA can explain what a detention does and does not affect.
When it comes to protecting the rights of vulnerable people, every moment matters, and having the right legal team in your corner makes all the difference. Whether you’re navigating a Court of Protection case, a Mental Health Tribunal, or a complex Deprivation of Liberty matter, Welford Solicitors brings compassion, clarity, and decades of specialist experience to every case. Don’t face it alone. Reach out to our dedicated team today. Call us on 0116 274 5252, or find us at 298 Welford Road, Leicester, LE2 6EG.