Angina and unstable angina: recognising a dangerous change

It may appear as chest discomfort at rest, a first severe episode, or established angina that becomes more frequent, stronger, longer-lasting or easier to trigger. It can be part of an acute coronary syndrome and cannot be safely assessed at home.

A stable angina pattern is generally predictable: similar exertion or stress brings it on, and it settles in the expected way with rest or prescribed medicine. Unstable angina represents a meaningful change in that pattern. The discomfort may begin without exertion or fail to respond as it normally does. Symptoms can include pressure, squeezing, heaviness or burning in the chest, sometimes spreading to an arm, shoulder, jaw, neck or back. Breathlessness, sweating, nausea or light-headedness may occur alongside it.

Stop what you are doing and call emergency services. Follow the emergency instructions in your prescribed angina plan while help is coming, but do not delay the call to see whether symptoms disappear. Sit in a safe place, loosen restrictive clothing and have someone stay with you if possible. Do not drive yourself to hospital and do not take another person's medicine. Bring your medicine list or containers for the clinical team if they are readily available.

Treat chest discomfort as an emergency when it is new and severe, occurs at rest or during sleep, lasts longer than your established attacks, returns repeatedly, or does not settle after following your prescribed plan. The same applies when familiar angina suddenly begins with much less activity. Sweating, breathlessness, faintness, nausea or spreading pain add to the urgency. Symptoms can ease and return, so temporary improvement should not cancel an emergency call once a warning change has occurred.

Once the emergency team has assessed you, ask what caused the change, whether heart damage was detected, and whether medicines or activity guidance need adjustment. Confirm the exact symptoms that should prompt another emergency call and when follow-up with your usual cardiac clinician should occur.