What you describe is proteinuria which is a common condition with lupus. It filters protein out of your blood and causes edema.
I have the condition and gained 20lbs of water weight twice in just a few days. See a nephrologist and he will probably want to do a kidney biopsy to determine the level of damage to your kidneys. If caught early this is very treatable with an ace inhibitor like lisinopril. You will also be given a diuretic. There might also be a small amount of blood in the urine but most likely it will only show in lab tests and not be visible.
I had stage 2 damage ( there are 6 stages of kidney damage) but treatment has brought the condition completely under control the past 3 years and my kidneys function normally with no edema or further damage. This is a serious condition but is easily treatable. The biggest danger is not diagnosing and treating it.
My illness is MCTD which is lupus, scleroderma and polymyositis. This is called an overlapping connetive tissue disease. Those whose disease is less defined have what is called UCTD (undifferentiated connective tissue disease). Treatment is pretty much the same as for lupus and there is no way to know if your symptoms will develop into something more defined or not.
My potassium levels are low so don't know what to say. We all have unique blood chemistry and few are perfect models. AI diseases and the meds often throw things out of kilter.
I know it is difficult but take things a day at a time. Most of us have gone through diagnosis hell and the uncertainty that brings. Cleveland Clinic has a great reputation but every individual case is unique and many, like mine, can be very challenging. Of course, the first thing is that I am a man and definitely in a small minority for lupus. Not quite so skewed for the other diseases.
Mixed connective tissue disease (systemic lupus, scleroderma, polymyositis), Raynauds phenomena, Hypertension, Barrett's esophagus.
Meds: prednisone 5mg, 50mg imuran, Lotrel 40/5mg, maxide 37.5/25mg, folic acid, potassium, aciphex 20mg, multi vitamins.
Maintain your optimism and you can beat the odds.
"Although the world is full of suffering, it is also full of the overcoming of it." Helen Keller