Thanks for the query.
The function of kidney, is the remove toxins from our body and to maintain the fluid balance. Two basic parameters are used to assess the kidney function - Urea and Creatinine (some use Blood Urea Nitrogen). If these are abnormal renal function is said to be impaired.
Proteinuria (or albuminuria i.e. a condition when protein is excreted through the urine) can occur in
kidney dysfunction.
In this case I would like to know the following:
1. The age of you husband.
2. What are his exact urea and creatinine levels, and what is the quantification of his proteinuria
2. Whether he suffers from any comorbidities like Diabetes or
hypertension (both can lead to kidney dysfunction).
3. Whether he has any symptoms like fever, burning during urination or urinary frequency/urgency/retention. These are symptoms of
Urinary Tract Infection, which can lead to renal impairment and proteinuria. Whether he suffers from
Prostatomegaly.
4. Did he have any similar renal impairment in the past?
5. Whether he has been on any drugs like NSAIDs (i.e pain killers) for a long time
At this stage I would advise you to get a USG of Kidney/ureter/bladder done to check for any abnormalities like renal parenchymal disease. If you can provide any information about the above points then probably his underlying cause for renal impiarment may be detected. It is also advisable that you get his urea, creatinine and electrolytes (potassium, sodium) repeated and consult your
nephrologist along with the USG report. If there is a chronic
renal disease (due to diabetes/hypertension), ACEI/ARB drugs may be started for proteinuria.
Hope this helps.