Blood viscousity


I donated blood this morning. It’s the first time I’ve done it in a few years. Normally it takes me at least 10 or longer minutes to fill the bag. Today I was done in 3:40. The nurse and I both where shocked.

Any ideas why my blood was so eager to get out?


I want to point out that I am using a DIY soylent not Soylent. I have lowered the amount of omega-3s from 11g to a level that is generally considered safe ( 2.19g ) and plan to donate again as soon as the Red Cross will let me. I will report back then.


High-fat diets, especially if high in animal fats and saturated fats, can literally make your blood thicker. Even olive oil, a healthy fat, tends to make your blood thicker.

Conversely, diets high in omega-3 fatty acids and fish oil lead to blood that will be thinner. In fact, that’s one of the reasons that you have to be careful if consuming an awful lot of fish oil - you can increase your clotting time as well as increase the flow from bleeds. But in moderation, both of these effects are good for you.

This is (one small) part of why getting more omega-3’s is generally good for you; it’s easier for your heart to push blood through all your tiny capillaries - and for blood to reach all the nooks and crannies - if the blood isn’t thick and syrupy. And if you have fewer blood clots, you’ll have fewer heart attacks and fewer strokes, both of which are caused by clots.


My first guess would be vitamin K because its a blood thinner and its easy to not get enough through a typical diet.


@Tetsuo I’m more inclined to believe MentalNomad. A vitamin K deficiency would prevent my blood from clotting which wasn’t a problem. I take the dreaded soybean oil which gives me plenty of K. Conversely I take 11g of omega 3s which can reduce the viscosity of your blood. I think I need to rework my fat profile to include more omega 9.


Factors could also involve hydration, blood pressure, catheter gauge, vein selection or misidentification of an artery, etc.


@dakota0626 I forgot to mention this was done at the Red Cross. Taking blood is what they do all day everyday.

Its extremely unlikely I got the special ultra wide catheter or that the nurse hit an artery or picked a weird vein. She took it from the normal vein near my elbow.

My hydration would of kept me from having a longer than normal draw not an ultra fast one.

High blood pressure seems unlikely as well. I would of had to of had dangerously high blood pressure and they would of caught that when they checked it.

If it was an allergy I would be showing other symptoms which I’m not.


You’ve never done IVs then. :wink:

The veins are in the antecubital region also run along a couple arteries. It’s very easy to be an experienced care provider and hit one by mistake, happens all the time.

The catheters are sized in guages, a 24 guage has a greatly reduced flow compared to a 18 or 20, or even a 22. I don’t know what they used or if they are allowed to use different sizes based on their confidence levels as we can in EMS, but that can make a huge difference as well.

Your hydration would have resulted in a faster flow, not a slower one assuming you were hydrated. Dehydration = less fluid = thicker blood = slower draws.

Blood pressure doesn’t need to be dangerously high to have an effect on draw rates.It’s actually about stroke volume than blood pressure when it comes to that.

I never stated anything about allergies. I am merely stating more likely variables than Soylent making you have superhuman blood abilities.

  • Signed your neighborhood paramedic.


Thank you for the explanation. I really do appreciate it. Given what you said it’s not as impossible she hit an artery as I thought. My veins roll and she initially missed the vein an had to hunt for it possibly hitting the artery.


That should have been apparent based on the color of the blood. Arterial blood is brighter red than venous blood due to the presence of oxygen. You also would have probably taken longer to clot when the needle was removed as the blood would be forcefully pumping in the arteries rather than the more passive flow in veins.


@leecauble1 the blood was the normal dark purple and the clotting was normal. Darn.

@dakota0626 another pease of relevant info I should of mentioned earlier but didn’t. I’m using a DIY soylent not Soylent. I’m using (s)oylent Green.


Speculation is all well and good, but if you really have medical questions and concerns you should be consulting your doctor.


Agreed. I do plan on bringing it up to my doctor when I go on the 7th.


Arterial blood is typically brighter yes, but the clotting part varies. The 22 and 24 gauge needles are not a big hole for blood to shoot through either.

Even after a run of the mill blood draw the skin closing around the puncture site is typiaclly enough to prevent more than a small dot of capillary bleeding from breaking the skin. The bigger sizes 18 and up bleed more but are used for IVs vs blood draws typically.

I have have witnessed and done it myself during blood draws, and granted one time, the force of the blood pumping did forcefully shoot a vacuum tube off of a collection set which was impressive, the other times a bandaid held and the blood clotted, just fine.

Veins also have different diameters too, smaller veins have less flow than bigger ones. There are just a variety of variables in play.


I like your point about hydration too. I’ve gone in to get a draw after a summer run and been dehydrated enough that they couldn’t get the blood out. Many gulps of water later and the blood flowed fine. Taught me a vivid lesson about hydrating properly during exercising.


Well after reading this thread I am feeling decidedly light headed. Are the effects blood loss able to be spread by Internet forums?


From what I’ve read, vitamin K is not a thinner; somewhat opposite, it’s a clotter. They give vit K to newborns in the USA to reduce the risk of hemorrhage (I did not allow my babies to be given the vit K shot, but listing the reasons would veer too much off the topic).

People on prescription blood thinners are cautioned against supplements that include vitamin K. But the reason isn’t that vitamin K will amplify the effect of the blood thinning medication; vitamin K will actually work against the thinning of the blood that the medication is intended to occur.


thanks for clearing that up, wikipedia confirms what you said.

Clearly the vitamin k content is not the issue.


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