Information for the public

Initial assessment

Urgent care

The healthcare professional assessing you after a blackout might be your GP, ambulance staff, or staff in the Emergency Department. If you have injured yourself or have not fully recovered consciousness, or the healthcare professional thinks that you have a condition that needs immediate attention, they should arrange the care that you need.

Gathering information about your blackout

If you have had a blackout, the healthcare professional who assesses you should ask you and anyone who was there at the time to describe what happened. They should ask about:

  • what was happening when you lost consciousness, such as whether you were sitting or standing

  • any warning symptoms you had (for example, were you sweating or feeling warm or hot?)

  • your appearance when you were unconscious (for example, your skin colour and whether your eyes were open or shut)

  • whether you moved, bit your tongue or hurt yourself when you were unconscious

  • how long you were unconscious for

  • whether you felt weak down one side or felt confused while you were recovering.

Questions you might like to ask your healthcare team

  • Why did I have a blackout?

  • Will a blackout cause any long-term problems?

  • What should I do now?

  • Can I drive?

  • Can I continue to work?

Your description of what happened, and any information from witnesses, is really important and will help the healthcare professionals who are carrying out your assessment to confirm whether you have had a blackout and may also help them decide what could have caused it.

What you can do to help if you have had a blackout

(you may be able to get checklists to help you with this from the organisations listed in More information)

  • Describe clearly what happened when you lost consciousness.

  • Give as much detail as you can about your blackout, for example, how long you were unconscious for, and how you felt before and afterwards.

  • If you can, provide contact details for anybody who was there when you had your blackout so that they can also describe what happened.

  • Give as much information as you can about:

  • any previous blackouts

  • your medical history

  • any medicines you are taking and why

  • any family history of heart problems.

  • Follow the advice you are given by healthcare professionals, for example, on what you should do if you have another blackout, how active you should be, and whether or not you can drive.

  • If you haven't yet had a diagnosis, or if your healthcare professional asks you to, try to get someone to record any future blackouts that you have (for example, by getting a video recording of your blackout using a camera in a mobile phone or a detailed description of your blackout from a witness).

  • If you have fainted or been diagnosed with 'situational syncope' (see Diagnosis after the initial assessment), keep a record of your symptoms, when they occur and what you were doing at the time so that you can understand what causes you to faint. You may be able to avoid trigger events.

History taking, examination and tests

What the healthcare professional should do

  • Take a history.

  • Examine you (for example, by checking your vital signs such as your pulse rate, breathing rate and temperature, and by listening to your chest).

  • Offer a 12‑lead ECG (ECG is short for electrocardiogram; this is a test to record electrical signals from your heart and check for any problems).

  • Offer other tests depending on your condition.

The healthcare professional should ask you about any previous blackouts, your medical history, any family history of heart disease, and any medicines you are taking. They should also offer you some tests to help them find out what caused your blackout.

The tests you are offered will depend on your condition and whether or not you have any other problems that are not connected to your blackout. You should not normally be offered a test called an EEG at this time (EEG is short for electroencephalogram; this is a painless test that records the brain's electrical activity).

The healthcare professional should discuss these tests with you and explain what they are for. A record should be kept of all of the information that you and any witnesses provide.

If an ambulance was called for you when you had your blackout, the ambulance staff should take you to the Emergency Department unless they are sure you fainted or had a type of blackout called 'situational syncope' (see Diagnosis after the initial assessment), in which case they should suggest you see your GP.

Copies of your records should be given to you and whoever is taking over your care. You should receive a printout of the ECG recording and copies of the results of other tests with your records.

Urgent referral


In certain circumstances you should be referred within 24 hours for a specialist cardiovascular assessment (this is an assessment of the heart and blood vessels). This applies when:

  • your ECG shows that something may be wrong with your heart

  • you have heart failure (reduced efficiency of the heart's pumping), or have had heart failure in the past

  • you have a heart murmur (an extra or unusual sound during a heartbeat)

  • there is an inherited heart condition in your family, or any family members have died from heart problems at a young age (under 40)

  • your blackout happened during exercise, or

  • you have new or unexplained breathlessness.

If you are over 65 and had no warning symptoms before you lost consciousness, you may be referred for a specialist cardiovascular assessment within 24 hours.

Diagnosis after the initial assessment

It may be possible to make a diagnosis of one of the following conditions after the initial assessment and without further tests.

Blackouts that are faints

You may be diagnosed as having fainted if your assessment doesn't show any other reasons for your blackout and if:

  • you were standing for a long time, or felt warm or hot or began to sweat before you lost consciousness

  • there were factors that may have triggered the blackout, such as pain or a medical procedure, or

  • you have been able to prevent previous blackouts by lying down.

Blackouts caused by specific situations

Sometimes blackouts occur in specific situations, for example, when coughing or swallowing, or straining when passing urine – this is known as 'situational syncope'. If this happens to you, and your assessment doesn't show any other medical reasons for your blackout, you may be diagnosed as having this condition.

Blackouts caused by a change in posture

Sometimes when a person changes posture from lying to sitting, or from lying or sitting to standing, they have a large drop in blood pressure. The medical term for this condition is 'orthostatic hypotension'. This may cause light-headedness (dizziness), a fall, or a blackout. If the healthcare professional suspects that you have this condition because of your history and your assessment, they should offer further tests that involve checking your blood pressure while you are lying down and standing to help them with the diagnosis.

What happens next

You won't need any further tests or treatment if you have fainted or been diagnosed with 'situational syncope' and your healthcare professional isn't concerned about anything else. If the person you saw about your blackout was not your GP, you should be given a copy of your patient report form and your ECG printout to take to your GP. Your GP should offer to arrange an ECG within 3 days if you have not already had one.

However, if you have been diagnosed with 'orthostatic hypotension', you may be offered further tests and treatment; the healthcare professional should discuss these with you.

If you fainted or have 'situational syncope'

You should be given some information on what may have caused your blackout. You should also be advised:

  • about possible trigger events and how to avoid them

  • to keep a record of your symptoms, when they occur and what you were doing at the time so that you can understand what causes you to faint

  • to see your GP if you haven't already done so or if you have another blackout.

If you have 'orthostatic hypotension'

You should be given some information on what may have caused your blackout. The healthcare professional should also discuss with you the possible causes, especially any drugs you are taking that may be causing your blackouts.

They should discuss with you what this diagnosis means for you and treatment options available to you.

You should also be given some advice about what you should do if you have another blackout.

If you have not been diagnosed as having fainted or as having 'situational syncope' or 'orthostatic hypotension' (see Diagnosis after the initial assessment) after your initial assessment, you may need to see a specialist.

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