Here for someone

A sudden change · England

They are suddenly behaving very differently

What to do when someone's mood, energy, speech, sleep, movement or behaviour has noticeably changed.

Short answerA sudden change from someone's usual behaviour matters, even if they seem happy rather than distressed. It can have many possible causes. Do not try to diagnose it from a list of signs. Describe exactly what has changed, how quickly it happened and any recent illness, hospital treatment or medication changes to the right healthcare service.
If they are in danger now: call 999. If they have suddenly become confused, call 999 or go to A&E. For urgent mental-health help that is not an emergency, call NHS 111 and select the mental-health option.

What to do now

  1. Check whether anyone is in immediate danger. If they may harm themselves or someone else, are impossible to keep safe, or have suddenly become confused, use 999 or A&E.
  2. Write down what is different. Note when it began and changes in sleep, speech, movement, energy, eating, drinking, confusion, unusual beliefs and safety. Use examples rather than trying to name a condition.
  3. Check what changed beforehand. Include recent illness, a hospital stay, missed or newly started medicines, dose changes, alcohol or drug use and a major lack of sleep.
  4. Contact the most relevant service. After a recent hospital stay, try the ward or team named on the discharge paperwork. Otherwise contact their care team or GP. If it feels urgent or you cannot reach them, call NHS 111 and select the mental-health option.
  5. Do not change their medicines yourself. Ask the prescriber, ward, GP, pharmacist or NHS 111 for advice if you are worried about a medicine or side effect.
Sources: NHS

NHS: where to get urgent help for mental health

NHS: sudden confusion needs immediate medical help

NHS: you can call 111 about someone else

More on this

They seem unusually cheerful, energetic or talkative

A person does not need to look frightened or unhappy for a marked change to deserve attention. They might seem much happier, more sociable, more active or more talkative than usual. What matters here is that the change is pronounced and out of character, not what diagnosis might explain it.

Notice whether they are also sleeping much less, speaking unusually quickly, becoming hard to interrupt, moving constantly, making uncharacteristic plans or seeming unable to slow down. Report what you can actually see and hear. Do not tell services that the person “must be manic” unless that is already part of an established diagnosis and care plan.

Who to call, and what to say

For this kind of change, call:

  1. The number on their discharge paperwork if they have recently left hospital. This may be the ward, crisis team or another named service.
  2. Their existing mental-health team if they already have a care coordinator, community team or crisis-team contact.
  3. NHS 111 and select the mental-health option if it feels urgent and you cannot reach an existing team, or they do not have one.
  4. Their GP if advice is needed but the change is not urgent.

Call 999 only if there is immediate danger, a life-threatening medical emergency or sudden confusion.

When the service answers, say who you are calling and why:

“I am calling for urgent advice about someone whose behaviour has changed noticeably. This began [when]. They are normally [brief description], but now they are [specific examples]. They have slept [amount], and there have been these recent changes to their health, treatment or medication: [details]. I am worried because this is very unusual for them. Which service should assess them, and how urgently?”

If they have recently left hospital, add the ward and discharge date. Have the discharge paperwork and their medicines nearby if possible.

If they say they feel fine

Do not argue about whether they are unwell. Keep the conversation about the change you have noticed: “You seem much more active and you have hardly slept. That is very different for you, and I'd feel better if we checked it with the team.”

You can still pass factual concerns to their GP or care team even if they do not want you involved. Confidentiality may limit what the service can tell you back, but it does not stop them listening.

Why this page does not suggest a diagnosis

Changes in behaviour can have mental-health, physical-health, medication, substance-related and other causes. Similar outward behaviour can arise for very different reasons. A website cannot safely decide the cause.

This guide is designed to help you notice a significant change, describe it clearly and reach an appropriate service. Condition guides are for understanding a diagnosis the person already has, not for matching someone to one.

While you are waiting for advice

Keep things calm and reduce avoidable stimulation. Avoid a heated confrontation or trying to prove that their behaviour is abnormal. If it is safe, stay in contact, encourage food and fluids, and keep the discharge paperwork and medicines available for the clinician.

If the behaviour escalates, they become confused, or the risk changes, seek more urgent help rather than waiting for a routine appointment.

And you?

Seeing someone change suddenly can be frightening. Tell another trusted person what is happening if you can, and visit Support for you if you need help carrying it.

Here for Someone is an independent information project. It cannot identify the cause of a change or diagnose a mental-health condition. This page covers urgent routes in England; arrangements differ elsewhere in the UK.

Sources checked: 29 August 2026

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