Why are my veins too small?!

October 21, 2007 8:21 AM

Would prolonged laxative use cause my veins to become more narrow?

A couple months ago when I tried to donate blood, I was turned away because my veins were too small to draw blood without causing major bruising.

They said that not drinking enough water was probably the cause of my small veins. However, I already consume probably a gallon of water a day, so I left somewhat confused.

Prior to this incident, I had been using laxatives (senna tea) daily for a few months in a lame attempt to lose weight. Could my use of laxatives have caused my veins to constrict? The only reasonable theory I could come up with was that the laxatives help flush water weight, so even though I was drinking more than enough water I was probably super dehydrated some how anyway.

I've since stopped the laxative use, and I'd like to try to donate blood again. Can my veins go back to regular, pre-laxative, blood-donating-size?

But I was also thinking that maybe my veins are just small to begin with; I've never donated blood before so it's not like I was successful in a previous blood donation attempt.

All I want to do is donate blood GOSH DANG IT! Anyone have any ideas on this? Any small veiners out there?

posted by anonymous to health & fitness (6 answers total)

I have no ideas on the laxative use, but I've been told every time I give blood/draw blood/etc. that I have tiny veins. They used pediatric needles on me for years. I've never had a problem giving blood.

I think it depends a lot of the skill and confort level of the phlebotomist and their favorite spot to draw from.

Blood donation places tend to be of the "anything that's remotely off, don't take the blood" mindset, so I wouldn't be too concerned.
posted by Gucky at 8:44 AM on October 21, 2007

When folks are seriously ill sometimes you need to have an IV in or take blood out. Even if the veins are small. What young doctors learn in this situation is that there can be an amount of difficulty involved in venipuncture. If a person is dehydrated the veins can look small that day. Some people really do have small veins, or a lot of subcutaneous fat that makes the veins harder to see. Other people have veins that squirm right out of the way of the needle.

For whatever reason the nurse took a look at your vein and decided that she didn't want to try it today. For all you know, it had nothing to do with you at all. Maybe you came at 4:30 but this nurse wanted to take off early at 4:45, or something. It probably won't be an issue the next time you go to donate blood.
posted by ikkyu2 at 8:51 AM on October 21, 2007

I also have small veins and have had varying degrees of success with giving blood. Some people get the vein without much of a problem and some only get it after repeatedly stabbing me in both arms, leaving massive bruises. When I've needed to have blood taken at the doctor, I've had times when the person taking blood gave up on my arms and resorted to the back of my hand.

However, this has not prevented me from donating blood. I'm up to 2 gallons so far.
posted by triggerfinger at 9:16 AM on October 21, 2007

Long time laxative user (sporadically), long time blood donor, never a problem with narrow veins.

Like ikkyu2, I'd recommend trying again. Do make sure you're hydrated; the only time I've had any trouble donating was when I didn't pay attention to hydration, and the trouble I had was that it took *forever*. (Though my grandma never drinks water and was apparently born to give blood; no slow-going for her.)

Did they try both arms? Did multiple nurses have a go at it? Once or twice, for no reason I can explain, they've taken several tries on me before they got a vein.
posted by iguanapolitico at 9:18 AM on October 21, 2007

I donate blood, don't use laxatives and I find that the level of hydration when I donate is THE deciding factor in how much of a hard time I have. Drink lots of water = totally simple. A little thirsty [like wake up and have coffee and no other fluids] = pain in the ass. Just being normally hydrated will do the trick, it's not really that your veins have shrunk, though they may be naturally small and/or a little hard to reach.
posted by jessamyn at 9:29 AM on October 21, 2007

yes, you were probably too dehydrated from the laxatives. good for you for stopping--it's a very unhealthy way to lose weight, even if the product is a natural one.
posted by thinkingwoman at 10:38 AM on October 21, 2007