What would make a finger turn white for a couple of minutes without apparent cause?

This is a medical question but it’s about somebody else. I can’t go to a doctor to get somebody else’s finger fixed, obviously. But it has me wondering now.

About 5 times now over the last couple of months, one of her fingers (always the same one) will suddenly turn extremely pale from approximately the second knuckle from the end, out to the end. It is a striking color contrast and we’ve taken pictures of it a couple times. It also goes numb. In a minute or two, normal color starts returning somewhat unevenly and within another half a minute everything looks normal.

She hasn’t noticed any potential cause in common between these events. They’ve happened day and night, while she was doing things and while her hand was idle, and she has no other conditions that strike us as related. She’s mid 30s and has high blood pressure and high cholesterol, both being treated and under control. She did break this finger years ago but it seemed to heal normally at the time and has given no trouble since.

I am bugging her to go to a doctor, and she probably will sooner or later, but it also has me very curious - could there be some muscle cramp pinching off a blood vessel? But I don’t think there are any muscles in the fingers themselves, only tendons leading to muscles further up, right? Could she have some weird geometry in there that occasionally lets a vessel get snagged?

Is there some exercise or trick she could try during the seconds this is going on, that would shed light on this mystery?

What could be the mechanism behind this?

Maybe Raynaud’s phenomena?

IANAD.

I don’t know how it could happen, but I assume it turning white means there is no blood flow. If that’s the case, she might be causing long term damage. It potentially could mean…long term…amputating the finger.

She really needs to get it checked out. I know you can’t make her do that, but maybe you can convince her that going to the doc is better than risking losing a finger…?
-D/a

I second Raynaud’s. It’s far more common than most people think, and the symptoms can be exactly as described. But a doctor that can examine her would be the best way of being sure.

cold can trigger Raynauds. see if it can be caused to occur holding on to something frozen.

I have Reynauds, but I’m wondering if it may be something else because it seems to be totally random and it’s just the one finger.

But IANAD and all that.

Does anyone know if Reynaud’s can affect just a single finger? I know 3 people who have it and in those cases all their fingers are affected.

I have Raynauds and it affects my hands at the knuckle area turning the skin red and it lasts all winter. When my feet get very cold, it affects only the 2 toes that I have broken in the past - one on each foot. They turn light purple.

Why not call the doctor’s office, ask to speak to a nurse and get an opinion on whether or not an appointment seems necessary?

LSD?

Thanks to Bill Dorr and the other proponents of Raynaud’s. It sounds correct and some of the pictures with the Wikipedia article look pretty close. I think this will get her to a doctor to check it out. Looks like Raynaud’s could be serious, though on the basis of what I read, I guess the doctor will probably say 1) that’s what it is, and 2) no need to do anything if it stays like this. Of course, if I knew for sure, she wouldn’t need a doctor…

Has she been taking large doses of vitamin B6 (more than 200mg per day)? That can cause this if done continually. It usually stops doing this after the B6 is discontinued after a week or so. But taking large amounts of B6 every single day can eventually cause permanent neurological problems.

Raynaud’s. My wife has it - one finger goes white. For anywhere from a few minutes to a few hours. Triggered by cold.

Huh, I had a boss who had a finger like that. Just one finger.

Are you a part time driving instructor for a high school?

Does this person smoke?
~VOW

Another vote for Reynaud’s, which I also have.

It can be serious and it can also be not a big deal at all. She’ll learn to keep her hands warm and that’s about it. However, it can be a symptom of several different autoimmune disorders so a visit to the doc for bloodwork might be advisable.

Yes. Why?

was she trying to phone home?

Nicotine causes constriction of the capillaries in the extremities. Often, quitting smoking can reduce Reynaud’s symptoms almost completely. Smoking can cause Reynaud’s or it can exacerbate it (if someone has it as a symptom of an autoimmune disorder).

Autoimmune disorders that can present with Reynaud’s as a symptom:
•Scleroderma
•Lupus
• Rheumatoid Arthritis
• Hypothyroidism

My mother has this - when the finger turns white it also gets very cold to the touch (which would make sense if the lack of color is due to lack of blood flow). It can last for several hours to a day for her.

I will mention the Reynaud’s to her as an idea…