Fell then blacked out for the first time-scared

I would go to the ER. It definitely doesn't hurt to get a Doctors advice!  The shock of the fall has happened to Me and somehow I ended up with my sodium going low. I guess or my sodium being low lead to fall!  That is more likely!  

People who  have dysautonomias pass out at the sight of blood, its a trigger, and because you were stood the blood first pools into your ankles and legs, then when you got up, it hadnt corrected quickly enough which, could be a sign of a dysautonomia, so,  it then lowers the blood pressure so, you have less oxygenated blood going to the heart and the head, and that is when you go hot dizzy and sick.   Depending on the type you may have, it can also, at, that time of passing out make your heart slow massively, by any chance did you notice this??  If you have a dysautonomia you would have experienced attacks like this in the past, either after inury, some sought of emotional shock or, trauma, and the  sight of blood.  Hot weather, and hot baths can be a trigger, also after eating large meals, and standing too long, you may also find you tingle all over as well, and the ringing in the ear can be part of the symptoms.  Dont think you need to go to the hospital, however, you could discuss it with your GP, and ask could it be a dysautonomia?  im guessing you could have the same as me, which is, vasal vagus syncope, read up on it, and read up generally on dysautonomias as there are many different forms.  On the otherhand however, if you have never experienced symptoms like this before, it is unlikely its an actually condition that you have developed, but its not totally out of the question, but normally if this has been a one off occurence then, its more than likely  caused by the shock of the trauma and the way your nervous system has responded to it, sometimes it happens so quickly we dont realise its happened because our nervous systems have been quick to react.  People with dysautonomias are made aware that their bodies are going into shock for something as small as a finger prick, because our nervous systems have been to slow to react to it.  So, if it came on minutes rather than seconds, after the inujury then it could well be a dysautonomia.  Dysautonomias are a malfunctioning autonomic nervous system, and the nervous systems that can be affected are, the sympathetic and parasympathetic  systems, sympathetic is our fight or flight system, which, is why you felt like you were having a panic attack, which also caused the ringing in the ears, then later when you are over the shock etc, you parasympathetic nervous system takes over, and you get the rest and dijest symptoms which, is when you feel less stressed and more relaxed and tired.