Collapsing has a range of causes. Usually it’s because a person has fainted, and they recover quickly, but it can be due to something more serious.
Call triple zero (000) for an ambulance if someone:
- collapses while sitting or lying down
- has a seizure
- has chest pain or palpitations
- develops a sudden, severe headache
- has problems breathing
What is a collapse?
You collapse when you fall down for no obvious reason (for example, you have not had a trip or fall). A collapse may happen when you become unconscious for a few seconds, such as when you faint. You might fall to the ground and not respond to sounds or being shaken. Your pulse may become faint and you might even stop breathing.
A person collapses when their brain isn’t getting enough oxygen. When you’re on the ground, it’s easier for the heart to pump oxygen to the brain.
You should always seek medical attention if you collapse — the sooner, the better. It could be a sign something is seriously wrong, and collapsing is a common cause of injuries, especially in older people.
What causes a collapse?
Fainting occurs when the heart rate drops and the blood vessels widen. This causes blood to pool in the legs, meaning less blood reaches the brain. Fainting is also called syncope. It can be caused by triggers that include heat, standing for a long time, seeing blood, or a shock. It can also happen when you stand up quickly, especially if you are tired, dehydrated or have low blood pressure or low blood sugar.
Very occasionally, people collapse without losing consciousness — their muscles just give way. This can happen due to problems with generalised weakness and frailty, a problem with the heart or brain, a seizure or an issue affecting the inner ear.
Other, more serious, causes of collapse include:
- a heart attack
- a stroke
- a seizure
- a major illness
- an injury or accident, especially if there has been a blow to the chest or head
- a drug overdose
- alcohol poisoning
If someone collapses, follow these steps. You can remember them by thinking “Doctor’s ABCD” (for DRS ABCD).
|Letter||Representing||What to do|
|D||Danger||Ensure that the patient and everyone in the area is safe. Do not put yourself or others at risk. Remove the danger or the patient.|
|R||Response||Look for a response from the patient — loudly ask their name, squeeze their shoulder.|
|S||Send for help||If there is no response, phone triple zero (000) or ask another person to call. Do not leave the patient.|
|A||Airway||Check their mouth and throat is clear. If there is foreign material, roll the patient on their side and clear the airway. If there is no foreign material, leave them in the position you find them in and gently tilt their head back and lift their chin to clear the airway.|
|B||Breathing||Check if the person is breathing abnormally or not breathing at all after 10 seconds. If they are breathing normally, place them in the recovery position and stay with them. If they are not breathing normally, call an ambulance and start CPR.|
|C||CPR||Start CPR: 30 chest compressions followed by 2 breaths. Continue CPR until the patient starts breathing or until help arrives.|
|D||Defibrillation||As soon as possible, attach an Automated External Defibrillator (AED) to the patient and follow the voice prompts. Do not leave the patient alone to fetch the defibrillator — let someone else bring it.|
After a collapse, you should seek medical attention as soon as possible. Your doctor or the hospital will run tests including blood sugar levels, blood tests, heart tests, a urine test to rule out an infection and x-rays, especially if you injured yourself when you collapsed. You may need to have intravenous fluids, medicines or oxygen.
Do not drive after you have collapsed. Make sure there is someone with you. Follow your doctor’s instructions on eating and drinking, and take any medicines they may have given you.
How to prevent a collapse
If you are likely to faint, avoid triggers like standing up too quickly or getting dehydrated. When you change position or stand up after lying or sitting, do so slowly and carefully.
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Last reviewed: July 2021