Causes of AVMs

Still confused about what causes an AVM. Some say it’s present before birth, but I haven’t located any studies that confirm this. Seems like guesswork to me, that everyone is just signing onto.

It seems to me that a trauma (e.g., use of vacuum during delivery) could cause trauma, and cause an AVM in a baby. Anyone know anything about this?


Hi Lee, my husband is the one that had the AVM. You know the same thing crossed my mind, since my husband was 52 when his made it’s ugly appearance, I wondered the same thing, not sure if they used forceps during the mid 50’s during delivery but since his was located close to the outside of the brain in the temporal lobe, it made me wonder. Or even a doctors hands. But if one is born with them, wonder what trimester they form and other thoughts such as that. Could a mom have bumped into something with her stomach to have caused something like this? All just thoughts and we probably will never know.
Blessings to you!

Hi Lee and Chanel. There is a defective gene that does run in some families on here…
Not everyone on here has that gene.
I was a 30 year old adult when my AVM burst 23 years ago. It broke my heart to see my Mother cry and say to me…I thought I did everything right. I have no doubt that your young son would want you both to be happy.
Please do not dwell upon the what ifs…bad things just happen sometimes.
I will continue praying for the both of you!

My son’s surgeon said that in most cases you have them from birth it is who you are how your veins are made in that spot…he also said he has seen them after a traumatic brain injury after something forcefully penetrates the brain; such as a bullet.

Or in my case a fist…The Drs that I was taken to seem to think mine were caused from blunt force trauma to the head because I had been in a very bad marriage…

Lee and Chanel, We’ll never now why an AVM is created. The ony thing I thought was how to get read of and as quickly as posible!

my neuro doc told me that my back stem viens are just remarkably thin; because of that there was always a risk of a bleed. Then its luck of the draw - some may have a bleed after 10, 20, 30, 90 years…whereas others may have none at all, despite having such pressure on the blood vessels. Luck of the draw… far as I have read and heard, this is something that happens before or during birth. Nonetheless, I agree with many when I say try not to think about when it starts. Trying to find and go through all of the research is tedious.

Normally there are very small capillaries between the arteries bring the blood to an area and viens taking the blood away. The arteries are thick walled, high pressure, and full of oxygen. When the blood gets to these tiny capillaries, the pressure is dropped as the blood goes through these tiny tubes. In the capillaries, the blood exchanges the oxygen with carbon dioxide. Then, the thin walled, low pressure, carbon dioxide filled viens takes the blood away.

As the AVM is a spot without capillaries, the high pressure from the thick walled arteries goes directly into thin walled viens. It’s similar to you mouth making high pressure air going into a thin walled balloon. Your mouth does not expand, but the balloon does. That is what happens to the viens. Just as the balloon can only grow so big before it pops, the same problem with the vien. Except, when it is AVM, the vien pops and bleeds into the brain, which is not good.

Back to the subject, the AVM is a spot that does not have capillaries. When the doctors dissect the brain (surgery) they see that there are no capillaries in that spot between the arteries and viens. They just see big arteries connected to big viens. It just takes awhile for the vien to expand and pop.

I have to confess I am a Chemical Engineer. When the doctor explained this to me, I translated it into the specific details with math and equations. That was a lot easier than accepting the problems in my brain. I was using mathematics as therapy.

My AVM doctor is involved in research and he says AVMs form during fetal development when the veins, arteries and cappillaries are differentiating and dividing and due to an unknown cause something goes wrong. Some AVMs are caused by trauma but most are not. They are not believed to be hereditary. I asked my doc if animals ever have AVMs and he said NO

hi there lee
i was also born with my avm however it covers the whole of my left leg, i dont know very many cases of this. no reasons given for why i have this painful condition


i lived in a haunted house in Germany when i was a toddler. that witch didnt like me at all. she tried enticing me to jump out a window. i was a little smart ass to her, so i wonder if she put it in my head?

I’ve also been wondering these things. They don’t really know much of anything, do they?? My mom smoked while pregnant with me, and I read somewhere that smoking is a risk factor that can cause your blood vessel walls to become thinner. Did anybody else’s moms smoke while they were pregnant with them? Just curious…

My Mom wondered if my scull closing up early as a baby had anything to do with my AVM. She said she had even taken me to the doctors to find out if I had something wrong with me as a baby, but that said I was fine. Almost 30 years later and my AVM shows itself. Makes ya wonder if things didnt form right but, I guess thats what an AVM is, a malformation.
Who knows if the two are connected.

They said I had mine since birth. I was diagnosed 4 years ago when I was 30. I wondered myself what was the cause.

The links at the top of this are good places to start:


i was asured that they develope when the cells form in the woumb, but i dont kno if i beleive that or if they beleive it. when i was getting ready to leave the hospital they asked me 20 questions. the one i really remember was did you ever bump your head really hard when you were a kid? of course the answer was yes. i lived in a haunted house when i was a toddler, i was a little smart ass to her. i think she stuck it in there. she tried getting me to jump out a window as well. but who knos. i agree they dont really kno were they come from. if they were positive they would not have asked me any questions. my surgen also told me if they dont rupture by 40 they will never rupture. i have read of more than one person who was over 40 when theres were discovered.

my daughter has multiple avms and cannot be treated . we were told by our surgeon that they form in development round about when the mum is six weeks pregnant (which didn’t make me feel good ! ) we were also told they are not hereditary. however i am a small person and my daughter entered the world weighing 10 lb 2 oz , after a long labour she got distressed and i was given an emergency c section and although we only knew about the avms when she had a bleed 2 years ago when she was 17 when she was growing up looking back now she always had problems and i often said i wondered wether or not the way she had been born had anything to do with it so it makes you wonder if it can be caused at birth.

I was 44 when mine ruptured…I’m now 47

Yes mine ruptured and I’m 66. Never had any idea of an AVM. No signs or warnings. What a shock!! I wonder why so late? I did fall off a horse when I was about 12. It was raring up and I let go. I slid on tiny gravel. I had a huge lump that was soft and squishy for several mths on the back of my head. My mom took me to the pharmacist and had him look at it, as we didn’t have a Dr. She was single with 5 kids. He said I definitely had a Concussion but the lump would dissolve eventually. That was that!! It is where I had my surgery. The vermis celerbellum. It may have been a bit higher. My Dr said they weren’t caused by trauma. But after reading so much I’m wondering because of my age. Sure hard to know!