There are all sorts of vascular problems with PN.

Some can cause PN, and some are the RESULT of PN.

When nerves become damaged, they no longer can control the
diameter of blood vessels.

But then there are autoimmune diseases, that cause inflammation of the lining of vessels..this is called vasculitis and often treated with drugs to suppress the immune system.

Thick blood from bone marrow disorders can make the blood too thick to get thru small vessels. This is called gammopathy.
Blood tests are used for this.

Eating very high carb and fat foods often will raise triglycerides in the blood and also cause sluggish circulation. So watching diet is important.

So there are many factors that affect circulation in small vessels. A careful diagnostic workup is needed to determine exactly which problem is present.

For some reason warfarin seems to bring people here with PN complaints. I don't know if it is because of its "poisonous" attributes or what, but we have had posters taking it and having worse PN, or new PN developing. I have not found it on lists of drugs that may cause PN... but every list I HAVE found is different from others! So it remains unexplained at this time.