Hi.
First of all we have to find the reasons for polyuria ( excessive urination) .The probable causes can be :
A simple test of specific gravity can tell. If less than normal this is called
diabetes insipidus.
The causes can be due to pituitary problem, diabetes,
kidney infection.
I would advise you to go for the following tests.
Blood : CBC, sugar, urea ,
creatinine, electrolytes
Urine - routine, microscopy, culture and sensitivity.
Ultrasonography of the abdomen and particularly the genito-
urinary system.
CT scan to confirm the diagnosis .
MRI of the brain and particularly for a pituitary s can
The pain in the body, heaviness and the tiredness in the body can be due to excessive removal of salts from the urine or an associated infection .
Facial and lower abdominal swelling can be due to anemia, hypoprteinemia or a more sinister cause of renal problems.
You need to undergo a thorough clinical / physical check up for vitals like blood pressure , pulse, all the investigations and proper medical management.