Dear all,

Today I needed to have some blood drawn for lab work.

Even this small amount seemed to have quite a big impact on my body, making me feel lightheaded and dizzy.

This made me think how debilitating this could be in a survival situation.

Can somebody explain why this happens and if there is something I can do to offset it's effects?

Thanks in advance for your help.

Regards,

B.

I used to have that reaction when I gave blood until a friend that works drawing the blood told me how to counter the effects.
You need to increase the iron in your body and the best way she said was to eat a steak. If you will eat the steak the day before, should help you counter the dizziness and light headedness.
When you go to give a pint of blood, they always check your iron level before you are allowed to give for those exact reasons.

Normally, only a small quanitity of blood is collected for tests, so my guess is that you weren't actually feeling the effects of blood loss (well, unless they actually did collect many tubes of blood). Many people also have a mental reaction to needles which manifests as physical symptoms. I normally don't mind needles, but one time, I was watching TV and a woman was having collagen injected into her lips. The camera did a close-up on the needle being stuck into this woman's lips over and over again and to my surprise, I soon ended up feeling weak and a bit nauseous. I was just watching the the needle on TV! Many people are similarly affected by the sight of blood or dead bodies and so forth. Even the brief pain of the needle being inserted can trigger certain physiologic reactions.

You are probably feeling dizzy due to low blood pressure. Whatever is actually causing the reaction, your blood vessels are relaxing, increasing the space available for blood in your ciruclatory system, and reducing the overall pressure. The classic method to deal with this lower pressure is to sit with your head down between your knees so your brain is at or below the level of the heart. Another method shown effective in clinical studies is to cross your ankles, then squeeze them, tightening the muscles in your legs and abdomen to increase the blood pressure to your brain. The flight suits of fighter pilots pulling high G maneuvers have air bladders that inflate and constrict their bodies to try and keep the blood from rushing to their legs and causing the pilots to pass out. Same principle.

I am not a doctor, so if you have concerns about this, please consult with a medical professional.

I'm not a medical professional, but my understanding is that we can lose up to 15% of our blood volume without noticable changes in vital signs. It sounds to me like the lightheadedness you felt was more a psychological as opposed to a physiological effect. The best advice I have for someone who is planning on donating blood or giving a sample or two, is to drink lot's of water at least 2 hours prior and stay away from coffee.

That is called a vasovagal response. It wasn't due to blood loss.

When your vagus nerve gets stimulated, quite often due to some kind of emotional reaction, your blood vessels dilate and your blood pressure drops. "fainting" falls into this category. If you were to check your vital signs during one of these episodes, you'd find your blood pressure would be down, and so would your pulse rate. Blood loss ("hypovolemia") on the other hand, results first in a rapid pulse, then a drop in blood pressure when the elevated pulse rate is no longer able to compensate for the blood loss.

I used to be a paramedic and dealt with this often. And yes, even having been a paramedic for many many years, the sight of my OWN blood in significant quantities makes me vagal out sometimes. "Vagal out" sounds more manly than "feel faint"! <img src="/images/graemlins/blush.gif" alt="" /> If you're sitting when this happens, it's usually easy to make yourself feel much better by bending over and putting your head between your legs. Not TOO far between your legs mind you, lest you generate the wrong impression for bystanders! <img src="/images/graemlins/tongue.gif" alt="" />

I participated in some clinical trials (only currently marketed drugs) and they have to watch how long the drug stays in the organism before being eliminated so they take a blood draw every 2 min, than every 30 min, etc. Sometimes they took more than what the donners give to the Red Cross when collecting blood. I never had problems, just sometimes headaches and feeling tired. But there was always one or two participant that felt dizzy and had to rest on a medical chair but it's only due to anxiety.

Frankie

I used to have a "cast iron stomach" as to my own blod loss - an in - well danm, guess I'm going to have to fix this-kinda thing (aka sew, glue, wrap)

But the last time I delt myself a good gash, I felt kind of sick, I mean, I got it done like usual - but it was like....Different in the "gut" feeling,(if this question had been asked 40- 50 years ago, I would have described it as a 'queer"feeling),, I did'nt like it at all, and I usually don't give much of a damn about my blood. Anyway, splashed somo water in my face & got er done...

I've patched myself (and others) up often enough over the years to include super-glue in all my kits, and have delt with several "borderline" serious injuries. All with good outcomes, but I understand when plain ole blood goes "creepey".

Simply put, in the amount you are talking about, it is all in your head. I donate blood all the time, never feel anything but ready to get out of there and on with my day. I have watched minor surgery on my own body (under a local) with no ill effects. My ex, on the other hand, would almost faint at the sight of blood, anyones blood. Don't know why some people are different, they just are. Don't know if there is any way to change it either...

OBG is right, it's all in your head. If it makes you feel better, take Geritol (iron for anemia) for a few days before you donate blood for any reason.

I had some serious blood loss (we won't go into details) a few years ago. Here's how it goes:

Psychologically, you may feel funny right away. This is just the fear factor. Settle down & apply pressure with a lump of bandage or a fingertip if it's small, or the heel of your hand if it's larger. If it requires the heel of your hand, you need medical assistance. Call 911 or have someone take you. You can't drive and hold pressure at the same time, so don't try to do it yourself unless there are simply no other options. Asking a stranger for help is an option.

If the bleeding is due to trauma, you may be feeling the beginnings of shock. Deal with the most life-threatening of the injuries first. You can bleed out from a large arterial tear in 1.5 to 2 minutes. You'll be unconscious very quickly, so move fast or give instructions to someone nearby, preferably not an idiot.

If you can't stop mild but continuous bleeding due to lack of access (internal, etc), and you can't get to medical attention right away, try to drink a cup of water every hour to keep your blood pressure stable. (This is from my doctor.)

As you continue to lose blood, you really start feeling sick. You will feel weak and probably start to vomit because you're going into shock. You'll be shivering. You aren't focusing on anything else except how awful you feel. If you are lying down and then you sit up, you will probably vomit and possibly pass out. Raising the victim's legs will help keep what blood is still in the body in the important areas, the chest, heart and brain.

If you need to apply a pressure bandage, see the instructions below. A pressure bandage is either held in place with your hand or a wrap-around bandage with a lump over the bleeding. The lump can be a stack of gauze squares, a handkerchief or a torn piece of clothing folded several times, etc. It doesn't have to be sterile, so use what you've got.

Please pay attention to the parts below where they mention peeking (don't), removing the bandage to apply a fresh bandage (don't), signs of flow restriction to the arm, leg or brain, and the inadvisibility of using tourniquets.

http://216.18.138.197/Bleeding_Control.asp

http://www.survival-center.com/firstaid/bleed.htm

http://www.permanente.net/homepage/handbook/healthwisehandbook/ch_03/ch_03_cuts.htm

A 150-lb person has about 5.25 quarts of blood in them. Most people can donate a pint (10%) with no ill effects.

If they lose 15-30% of their blood (3 cups to 1.5 quarts), they will probably look pale and have a rapid heartbeat, their skin will feel cool, and they may act odd. They should have IV fluids, but usually don't need a transfusion. Their own body can replace it in a week.

If they lose 30-40% (1.5 to 2 quarts), their blood pressure drops, the heart rate increases & their mental status gets worse. They will need both IV fluids and a blood transfusion.

If they lose more than 40% of their blood, they will need a lot of help to avoid death.

BTW, transfusions are a temporary loam of red blood cells to carry oxygen. Your body can replace them after a while, but until you do, you will find that climbing a few steps will make you sweat and pant! <img src="/images/graemlins/shocked.gif" alt="" /> So, don't make any plans for any immediate vigorous exercise.

Sue ("Liver? You want me to eat LIVER? YUCK!!!")

The autonomic nervous system is a funny thing. Most people can lose a significant amount of blood without many symptoms. In Vascular Surgery we have a saying- "It's not really bleeding unless you can hear it" Trust me- if it's really bleeding you really can hear it!

Small amount that is used to be drawn for blood work should not affected your body as much unless you have circulation problem, low red blood cell count or your body baroreceptors (receptors that measure your pressure and rely info to the brain) are extremely sensitive. Usually symptoms you describe is when people loose a lot of blood. Certain volume of blood (6 liters) circulates your body. Red blood cells carry oxygen to the vital organs (brain, heart, lungs, renal system, etc, etc) and remove co2. Any time volume of blood gets affected few things will happen if brain senses that oxygen supplies are not being sufficient. First. your heart rate will increase to circulate blood faster. Remember now your volume is less so faster turn around should bring equilibrium back. But since now your heart rate is faster, heart which after all is a muscle has an increased demand for oxygen which means that your respirations will increase as well. Last thing that will happen is vasoconstriction which is term we use when your arteries and veins decrease their lumen (diameter) in order to increase the pressure that is already low due to the loss of blood. That's why people with severe blood loss are cold and sweaty. Little capillaries on the outside keep shutting off one by one keeping blood out of unimportant organs (like skin) and maintaining fluid supply to important stuff.

Being lightheaded, dizzy or tingling is normal when your brain has too little oxygen due to dropping supply secondary to blood loss. It is also the same way you feel when you hyperventilate or there is too much oxygen there (anxiety, panic attack, hyperventilation). What I assume may have happened is that you gave some blood, there was some drop in the volume, your body overreacted and out of the sudden your brain got little too much of the oxygen which caused dizziness and being lightheaded. Or just vasovegal response... Mind you this would be my vague explanation without me knowing you medical history, vital signs, etc..

Now to combat blood loss in the field is nearly impossible. First of all bleeding must be stopped (kind of hard to do for internal bleeding). There are no over the counter available products for us to replace lost blood. Short of blood transfusion there is nothing that can save you. In the field we pump people full of fluids to maintain their pressure and circulating volume but our fluids have no means to carry oxygen. If you are with somebody who suffered sever blood loss and they are going into shock and the ways to treat the socks are: lay them down flat, elevate their legs, keep them warm and provide with oxygen.

Adults metal status and reaction to blood loss is a steady down line. They progressively get worst until they crash. With children their bodies will compensate very nicely for a long period of time for blood loss (healthy heart and excellent circulation) until they cross a crash point and deteriorate in a matter of minute. It’s important to remember that because it is very easy to overlook a serious blood loss with the child,

For many people it my be "all in their head" but we must remember that everyone reacts differently to many things, giving blood included. The first and only time I gave blood, I had sufficient iron in my blood and was not in the least squeamish about the sight of my own blood (I used to hold up my own vein for the doctors to take samples). However it took me over 1 week to recover, I had brain fog and felt lethargic. The exam I took the next day (yeah I know!!) was not at all difficult but I did rather poorly, it took me twice as long to come up with the answers, which is not normal. This for me was definately not psycological. I have not had this result with any of the tests that I have had since then either, some of up to five vials.

For most people it will not be a problem, however for a few, the loss of blood may trigger a reaction in something which is not normal with their bodies. It is easy for those who are in the medical profession to say that it is all psycological, which it is in many people, but without knowing everything about a person's body (which we can't) we should not say that it is only in their head.

Even the ancients knew that blood letting did some strange things sometimes. <img src="/images/graemlins/wink.gif" alt="" /> <img src="/images/graemlins/grin.gif" alt="" />

Susan,

Nice Post! Thanks for taking the time to provide the links.

Regards,
Comanche7

Welcome TomP. Input from another member of the medical community will come in handy around here...

Given the small amount of blood depletion you describe, I think the posters here who mentioned vasovagal response are correct.

Remember too that different people will have different degrees of response to vasovagal stimulation. When we were practicing IV sticks in EMT class they had us pair up with a buddy and sit on either side of a small table. There was a pile of IV gear there and we took turns placing IV catheters. It didn't bother some folks at all, while others just about passed out. My partner was doing fine until the instructor came by and grabbed the catheter I had placed to see how well anchored it was. My buddy turned white and almost passed out...! <img src="/images/graemlins/shocked.gif" alt="" />

Here is a reasonably good overview of the vasovagal response.

Thank you all for posting.

Some feedback:

Only a small quantity of blood was collected, so I probably was not feeling the effects of blood loss. <img src="/images/graemlins/blush.gif" alt="" />

I'm in good health, had a normal breakfast and was not squeamish about the procedure, or "the Needle" in particular. <img src="/images/graemlins/cool.gif" alt="" />

If it would be fear, would the body not react with constricting the vessels and elevating the blood pressure? <img src="/images/graemlins/smirk.gif" alt="" />

Whatever is causing the reaction, low blood pressure, sounds like a reasonable explanation. Next time I will try putting my head between my knees and/or crossing my ankles.

Regards,

B.