If you were born with a weak or narrow vein structure, your veins can suck down around the needle, temporarily blocking blood flow. You might also have trouble donating with small veins, because smaller veins make it extra hard to find a good vein, or to place the needle so that it doesn't slip out.
Most people can still donate blood plasma, even if their veins look too small at first. Here's how to enlarge your veins and arteries for plasma donation:
- Heat up your arm. When veins become overheated, they expand, and draw closer to the skin. Using a warm compress on the vein is helpful for bloodflow - though some technicians may be too busy for this. If you can, wrap a heating pad around your arm before donation, or dress in several layers of warm clothing to make your veins bigger.
- Hold off on drinking and smoking. Both smoking and drinking alcoholic beverages makes veins and arteries smaller and harder. 24 hours before donating plasma, stop drinking or smoking, and you'll have a much easier donation.
- Hold off on the caffeine. Similar to drinking and smoking, caffeine increases your heart rate, but restricts blood vessels, making plasma donation more difficult. Limit your caffeine intake to 1 or 2 beverages total 24 hours before plasma donation.
- Drink several glasses of water directly before donating. This is very important, as it lubricates the blood plasma, expanding the veins, and makes plasma donation a much easier and quicker process.
- Eat high protein foods the day of donation. Even though you drink fluid, the amount of protein in your blood is what keeps the fluid in the veins (it's called osmotic pressure), so what you drink stays where you need it.
- Take daily chestnut supplements. For small, problematic veins, equine chestnut is an herbal extract that is shown in studies to increase vein capacity and decrease irritation.
- Do exercise 3 days a week to increase vein depth. Exercise pumps your blood, which enlarges your veins, increases capillary flexibility, and improves overall blood cell circulation. Poor circulation and/or lack of exercise are more common causes of plasma blockages other than depth of the needle.
- Lose weight so veins appear "bigger." Weight loss is good for your health in general, and removes fat tissue that can block the visual location of the vein during donation. Your weight and genetics can make it difficult to find a vein for donation - so much so, that the phlebotomist may have no idea where to place needle - in these cases it is quite easy to miss, or to hit the vein at a bad angle, which can cause total vein collapse.
- Pump your stress ball. When your pump the ball they give you, you force blood back into the donation vein, plumping it up and making the your arm engorge with blood. If you have a constant need to pump your fist to keep pressuse, then the needle is too deep or your veins and artery can't keep up.
- Ask for a shallow needle insertion. If the needle is inserted too deep, it can restrict blood flow and cause the vein and artery to work harder which can cause fatigue and passing out. Some veins are harder to hit than others, and every phleb has a different "sticking” technique. The vast majority of the time, I get someone half-decent, and they find the vein the first time around.
That should help to plump up your veins and extraction of the blood will be easier.
Finally, if none of the above work, inquire about using an alternative vein location for your donation as it is likely an alternative site will provide better results.
Why Are My Veins Unsuitable for Donation?
Some people, genetically, are born with weaker or smaller veins than others - and some people are born with larger, and more flexible vein tissues. Due to genetics, some people just have poor, weak veins. This only affects the large return veins you can see however - the veins which transport the rest of your blood are likely fine.
Regardless of the vein size, blood can still be drawn. I personally have smaller and weaker veins, and can still donate, but sometimes it takes a few tries. If you can't donate, it's likely that you have a bad phlebotomist, rather than bad veins. Sometimes veins are "rolling," which means they have weak support structure, and move around, so the phlebotomist can stick the needle in at a bad angle.
On a more serious note: don't donate very often, and frequently take breaks, because it can really scar your veins over time and make it look like you have traction.
Collapsed Veins and Other Plasma Donation Complications
Just like when you use needles for other thins (think illegal substances), the plasma needle punctures the vessel, which causes scar tissues to form. This scarring is a serious risk to your health, and over time can also cause iron deficiency. Other complications like bruising, phlebitis (vein inflammation), and permanent nerve damage from sticking in the needle too far can also rarely occur.
After years of donating plasma, my veins have collapsed twice, causing significant pain. If you have collapsed veins, it might take longer to find veins for donation, especially in people who regularly donate. I suffered no other long term ill effects, however, other than having a small "dimple" of scar on my arm.
During the plasma donation process, it's possible for the needle to pierce through the vein completely. This causes nerve pain, large amounts of bruising, finger numbness, cold sweats, or even blacking out for a period of up to 3 min. They might totally rupture the vein in your arm which can leave a significant bruise that lasts for weeks.
They put the needle in my vein wrong once, and the machine didn't return the blood back to my vein like it was supposed to, it instead returned my blood into my arm's muscle tissue, because the needle somehow slipped and penetrated the vain.. So the blood failed to return to my vein, it was going into my arm, which caused mild pain, and later, the nastiest bruise you've ever seen.
What Happens During Donation?
A trained phlebotomist puts a sterilized, one-time use needle in your arm vein to extract the blood. Typically they hook up your median-cubital arm vein (not an artery) for blood plasma donation (it's located in the crook of your arm opposite the elbow). They are tiny fragile blood vessels leading just under the skin, as well as larger veins, from which they receive the donations.
While you sit and wait, the needle in your arm will draw your blood into a special spinning machine (a plasmapheresis machine) that separates your plasma from the whole blood, and platelets.
It's practically the same as giving blood, but after the plasma has been separated and removed, they mix saline with the rest of your blood and give it back to you. During this part of the process, you might get a metallic taste in your mouth and feel cold (so bring a sweater!) but it only lasts for a minute or two.
They also put thinners in the blood to keep it from clotting when it re-enters the vein, so look out for side effects from that.