Hello all. I'll make this as short as possible! I'm currently in the process of trying to figure out what has a caused a sharp and sudden decline in my kidney function. Last time I was checked a few years back my function was well over 90. Now it has fallen to 65. Back in October I had an extremely severe sinus infection that just would not go away. It lasted for several months. During this time my BP was insane high. Averaged about 180/110. And some days would creep over the 200 mark. And I've never felt so bad in my life. I was certain I was going to die. And likely almost did a few times. I figured this was the cause of my kidney damage. Or did the kidney damage cause all this? Who knows? I've taken BP meds all my life and it's always been extremely well controlled. My doctor did some blood work and doubled my BP meds to no avail. So while googling my symptoms I came across vasculitis. And I read that a certain subset of vasculitis can cause severe sinus infections along with kidney failure! It sounded exactly like what I had but the doctors never even mentioned it. I should mention that I also has Psoriasis and Psoriatic arthritis which can increase the chances of vasculitis I believe right? So anyways I made an appointment with my arthritis doc and expressed my concerns. He said it's possible but the only way to rule this out was with a kidney biopsy. He said the ANCA test could help, but was far from conclusive. And unfortunately I'm without health insurance so I will have to pay cash for all these test. My cheapest quote so far has been around 5 grand! So I'm not sure if I should do it or not. The doc also told me that it was insanely rare. In fact, he said his practice (which is rather large) has never even seen a case of kidney vasculitis and they have been open for over 30 years! He has seen many cases of other far less serious cases of vasculitis but never one involving the kidneys.
So fast forward to today and things are much much better. My sinus symptoms are gone. And although I still have severe BP spikes, they are short lived and do not reach anywhere close to the numbers I had back in the winter. In the winter my average BP was 180/110 with spikes of 200/120. Nowadays my average BP is about 130/70 with rare spikes of 160/90 or so.
So my question is, can vasculitis go into remission on it's own without treatment? I've read that vasculitis has a tendancy to go into remission with treatment and then often recurs later. But without treatment do symptoms typically persist? Basically I need to decide which test to have run. My reg doc wants me to have a kidney ultrasound and a stress test. And then there's the kidney biopsy. Sadly, there is no way I can afford all these. And I do not qualify for any type of financial assistance. So I must decide between with either the biopsy or the other two test. My reg doc was honest and said he has very little knowledge of any type of vasculitis not alone kidney involved vasculitis. He said he also has never seen a case of any type of vasculitis. Any advise would be greatly welcomed!! Thanks.
Here we go 
ultrasound for kidneys
Discussed water consumption with my kidney doctor
Kidney function dropping fast 
Lentils on kidney diet. 
