Loss of Consciousness

Sudden loss of awareness is a frightening experience. This can occur out of the blue though there may be a short warning. Any time there is loss or alteration of consciousness, contact should be made with an experienced medical practitioner who can diagnose the problem.

The two commonest diagnoses are vaso-vagal faints and epileptic seizures. There are other diagnoses. The history is vital because usually nothing is found on examination. If you are unfortunate to have an attack where consciousness is altered, then do everything possible to get a witnessed account of what took place. Even better if it is a family member or friend, see if they can write down the events themselves or visit the doctor with you. Never accept from a doctor that it was "one of those things". This is not an acceptable conclusion. It may be that the episode defies a clear diagnosis but then perhaps a specialist opinion is required. There is always a reason for every episode of loss of consciousness. It is the normality of the individual when they present to doctors that causes the problem.



The History

Knowing precisely what you were doing at the time that the episode occurred can be particularly helpful. For instance did it occur when you got up in the middle of the night? Did you feel faint or lightheaded before the episode took place? In the case of young women, was it around your period time? In all people, was it associated with having a blood test or seeing the dentist or having something painful happen? The person witnessing the episode may be able to report that you said something, even called out, looked pale and started sweating. If they have any medical knowledge, they might have taken your pulse. The observation of the pulse is perhaps the single most useful observation Unfortunately most people having a funny turn do not carry that information with them when being assessed later. If you have suffered loss of consciousness, then for whatever the reason, commonsense applies with regard to taking baths in locked bathrooms by yourself, going swimming without another adult knowing that you have had a problem and there is a legal requirement with regard to driving until the diagnosis is secure. Obviously if it is a simple faint that is finally diagnosed, then there will be no worries and there is discussion later on how best to avoid this situation happening again.



Vaso-Vagal Faint (simple faint)

A faint occurs because the heart and circulation have found themselves in a situation whereby the blood flow to the brain has been reduced. This can occur for a number of years beyond the brief of this discussion. The heart slows down inappropriately and if there is a strain placed on the circulation for whatever reason, then the outflow of blood from the heart will be insufficient for need. This reduced flow of blood to the brain means that the brain gets starved of the blood it needs. A feeling of faintness ensues which is designed to get the individual down on the floor or at least horizontal as quickly as possible so that the circulation to the brain is enhanced. If you ever feel faint, then if you do nothing more but lie on the floor and manage to get the legs gently above the head, then almost certainly you will prevent an actual faint taking place.

With a faint, usually there is a warning. An individual knows that something is happening and there may be a feeling of clamminess or sweating. If no action is taken to lie down, then there will be usually a blacking out of vision and a whistling or noise in the ears before consciousness is lost with falling to the ground. Somebody looking on may notice that there is a loss of colour with people looking "deathly" white as they collapse to the ground. Usually there is a rapid return of consciousness. It is possible to be incontinent of urine during a faint and if for any reason the body is stopped from being on the ground or there is an attempt to lift, it is possible for apparent seizure activity to take place. There can be jerking movements of the limbs but these are usually short-lived. There may be a loss of speech or confusion. None of these features would detract from a diagnosis of a simple faint.




There are no easy investigations that will diagnose a faint. Often an individual will have a low normal blood pressure. There may be a history in the family of fainting. Close attention to the history may reveal a feeling of faintness with a blood test or school vaccination in the past. A simple blood count may reveal a degree of iron deficiency anaemia or even just relative iron deficiency particularly in a young woman. Questions about the heaviness of periods often revealed that is the case. Sophisticated testing can involve doing what is called a tilt-table test. Usually under the supervision of a cardiologist, an individual is placed on a tilting table for some period of time and fainting can be induced by this manoeuvre which confirms the diagnosis.



Alternative Diagnoses

The alternative diagnosis to a faint is that there is a heart rhythm disturbance of greater significance. (See heart rhythm disturbance). This nearly always involves specialist referral to an interested neurologist or cardiologist or both depending on how each individual consultant works. I personally work very closely with my cardiac colleagues in diagnosing individuals who have "funny turns".




Fainting can occur under a number of circumstances. One of the most common situations is in young women associated with periods when they are a little anaemic. If a meal has been missed or there is excess tiredness or presence of alcohol in a hot environment, then all of these can be a trigger. Avoiding this combination may be all that is required. Making sure all blood tests are taken lying down can also prevent attacks. An individual just knowing what is happening may stop further episodes from happening. 

In older men, there is a condition called micturition syncope. This fanciful term just means that you faint when you get up at night to pass urine. The mechanism is getting out from a warm bed into a cold environment and then standing at the toilet to pass urine when there is a degree of prostate enlargement. The vagus nerve discharges which causes a slowing of the heart and there is a faint. The simple technique of sitting on the edge of the bed for a short time before getting up and then sitting down to pass urine will prevent this from happening. Some people can faint even with coughing or getting up suddenly and simple measures will prevent this as well.

Very occasionally individuals can faint for almost no reason and then it is necessary for a consultant cardiologist to determine this particular state and very specific treatment needs to be given. I must emphasise that the number of people in this situation are very few and far between.



What should others do?

I am frequently asked what other people should do if there is a faint. The simple answer is very little but make sure that the person suffering is in a place of safety and kept flat with the head turned gently to one side in case there is any vomiting. This rarely happens with a faint. Lifting the legs gently above the level of the head usually results in a very rapid return of consciousness. The absolute must is not to stand the person too quickly. They are not a horse and if they keep lying down for a period of time, they will come round and be able to sit up within a few minutes before returning to normality. The only other element to check if you do not know the person is to make sure that they do not suffer with diabetes. Hopefully they will have a card or a necklace around their neck or a Medic-Alert bracelet that would warn. Only in this situation would there be a need to try and administer sugar carefully. This definitely should not happen until there is returned consciousness in somebody who is undiagnosed. If there is any suggestion that consciousness is delayed even though the individual is lying down, then medical help should be urgently summoned.