Fainting is a short-term circulatory collapse in which the person concerned loses consciousness but quickly wakes up again. In some cases, memory for the time before fainting is temporarily impaired, but the person affected can usually regain their bearings very quickly afterwards.
A circulatory collapse can have various causes. In most cases, it is due to short-term changes in blood pressure or pulse, which are often harmless. However, serious illnesses can also be the cause, which is why further clarification should be sought, especially in older patients and those who faint repeatedly. Also
- a disturbance in kidney function,
- electrolyte imbalances and
- too low or too high blood sugar levels
can also be the cause of fainting. Circulatory collapses are often accompanied by a weakening of the holding tension of the muscles, which can lead to falls. Syncope should not be confused with circulatory disorders of the brain stem, epileptic seizures or a stroke.
A circulatory collapse is often heralded by certain symptoms such as
- paleness
- dizziness
- nausea
- increased sweating and
- palpitations
and heart palpitations. Some also report feeling black in the eyes. If you notice these signs, it is important to protect yourself. It is not uncommon for those affected to injure themselves as a result of fainting. An uncontrolled fall occurs and, depending on the position and surroundings, can result in minor or serious injuries.
Doctors therefore advise people to lie down or sit down if they show the above signs. With some illnesses, such as cardiac arrhythmia, these warning signs often do not occur. In these cases, serious injuries can result from falls. How long unconsciousness lasts varies from person to person. For most people, however, unconsciousness lasts no longer than one minute.
If the cause of the fainting spell (syncope) lies in the circulatory system, doctors speak of vasovagal syncope. In this case, the nervous system overreacts and there is a sudden circulatory collapse. Pain, anxiety and stress are among the possible triggers. Suddenly standing up, constriction of the throat and eating a large meal (mainly affects older people) can also cause syncope.
Apart from vasovagal syncope, heart disease is the most common cause of fainting. The cardiac diseases that cause fainting include
These heart diseases can cause a temporary reduction in blood flow to the brain.

By Bionerd - Own work, CC BY 3.0, Link
Other causes of circulatory collapse include
- Constriction of the blood vessels leading to the brain and
- Diseases of the brain such as brain tumors, strokes and inflammation of the meninges or brain.
In addition to disorders of the brain, heart and circulation
- mental states of emergency such as panic attacks,
- medication,
- hormonal fluctuations during menstruation and
- a large loss of fluids as a result of traffic accidents, injuries, fever or diarrhea can also lead to fainting.
can lead to fainting.
If you witness a person losing consciousness, provide first aid immediately. It is also important that you contact the emergency services, as fainting can also indicate a serious illness.
The first step is to check whether the person is responsive. In many cases, a circulatory collapse does not last long and the person concerned quickly responds to being spoken to. Blood flow to the brain is better when the patient is lying down , which is why the condition usually improves quickly. You should also elevate the patient's legs to further improve blood flow to the brain.
If the patient is unresponsive, call an ambulance immediately. You should always call an ambulance if you suspect an acute heart attack, cardiac arrhythmia or circulatory problems in the brain. If you cannot hear any breathing sounds or feel a pulse, start with chest compressions. Start with 30 compressions and then perform two ventilations. As many first aiders are unsure about mouth-to-mouth resuscitation, the recommendations have now been changed. It is sufficient to perform one chest compressions until the emergency doctor arrives. This alone can significantly improve the chances of survival of a patient in cardiac arrest.
If two rescuers are on site, it is also advisable to check whether a defibrillator is available nearby. Shock therapy can then be administered or prepared for the emergency services. The victim must then be cared for by trained specialist personnel, including emergency doctors and paramedics, and transported to the nearest hospital.
The treatment of a circulatory collapse depends on the cause. If the affected person is actually healthy and the circulatory problems are only temporary, then no special treatment is necessary. However, there are measures that can be taken to prevent syncope in the future.
It is often possible to diagnose syncope on an outpatient basis. If there is no life-threatening illness and there is no reason to assume that the circulatory collapse will occur again, care is provided on an outpatient basis. However, longer-term monitoring and further diagnostics are necessary for people with cardiac arrhythmia and other heart diseases. In this case, a monitor is ordered to monitor the cardiac activity.
If circulatory collapses occur frequently in a person or if serious heart disease is present, medication and the use of a pacemaker are necessary. A pacemaker can be applied temporarily from the outside, but it is usually necessary to insert a pacemaker under the skin by means of a minor surgical procedure. This is often performed under local anesthesia; general anesthesia is rarely necessary.
If you are prone to circulatory collapse and want to strengthen your heart and circulation, there are a number of things you can do. If low blood pressure is the cause of frequent syncope, it is important to train the circulatory system in a targeted manner. Training the circulatory system includes
- regular sauna sessions
- alternating showers with cold and warm water and
- sporting activities
It also makes sense to do gymnastics in the morning after waking up in bed and to take your time getting up. If you are one of those affected, drink enough fluids every day and make sure you consume enough salt. A daily fluid intake of 2 to 2.5 liters is considered ideal.
For many people affected, there are certain situations that favor the occurrence of circulatory collapse. These include, for example, staying in overheated rooms, standing for long periods and not drinking enough fluids. If you feel the first signs of fainting, it is important that you sit down or lie down. Tensing your muscles, crossing your legs and squatting can also avert an impending circulatory collapse.
These measures are often enough to prevent a circulatory collapse from occurring in the first place. In this context, medication is not considered to be a more effective alternative to purely physical measures. For this reason, doctors generally recommend these physical measures as the first step in preventing syncope.