Re: Adrenal Fatigue causes low back pain and weak knees.

 I think if you let adrenal fatigue go it turns into arthritis.

More complicated than that.  There are actually about 120 forms of arthritis, and of course they can have different causes.  Weak adrenals though can increase inflammation, which is what arthritis is.  Arthritis literally means inflammation of the joints.

Weak adrenals also adversely affect the immune system contributing to autoimmune conditions such as rheumatoid arthritis.