Are thin, healthy, people at a greater risk of undiagnosed kidney damage?

[bubblefoamyboy]

I am asking because I have a clear case of change in my urinary pattern, but the docs don't have an explanation when they look at the numbers (e.g. creat. 1.2).
Is there a more precise test to do? cystadine c?

I am thin.
Suddenly 6 months ago I started to have foamy (beer-like, but clear in color) urine - all possibilities outside my body already excluded; unless Earth changed gravitational intensity or something drastic like that.
Also, I had during this period a chronic exposition to anticoagulants.

My blood results are almost normal, but above my personal average (creat. 0.8). Every Physician agreed the amount of bubbles were/are not normal (by pictures). However they seem bound to the test numbers and cannot take into account my history and bubbles.

Since I had also symptoms like swelling below the eyes after salty food, I suppose something is not as it used to be.