Reynauds involves poor circulation in the hands and feet.
It is initially triggered by a virus, and here are some things possibly associated with it.
1) Strong connection to nerve problems of some kind. I have 'cell phone elbow' or an inflamed ulnar nerve on the right side and that has much worse Reynauds. The nerve issue costs a bit of fat and muscle though, and that may be the cause of the difference.
2) Strong association with increased muscle cramping from magnesium.
3) Some substances like Lion's Mane and Inulin have a complicated relationship with Reynauds which is hard to figure out.
Lion's Mane will initially improve systems related to Reynauds but may ultimately create a sort of dependence in which if you stop taking it then you will get more serious symptoms. In other words if the active compound in Lion's Mane were to become an essential vitamin millions of years in the future then Reynauds would become a vitamin deficiency symptom.
This separate section will include anecdotal information about the connection between nerve compression and Reynauds.
So called 'nerve glides' which move a compressed nerve back and forth have such a striking effect on the visible signs of Reynauds that obviously there is a connection.
Since I have a nerve on one side that is compressed both at the elbow, i.e., ulnar nerve, and the neck or shoulder, i.e., ulnar + another nerve, it's easy to research the effects of various overlaps between nerve compression and Reynauds which will be added to this page.