Hi, 
Thanks for your question. 
After going through your question, I can understand your concern. 
For better opinion I want to know
- Your age and gender. 
- why are you taking 
water pill. 
- Is there any 
diabetes, 
heart disease, Blood pressure or 
cholesterol problem. 
- Habits like smoking, alcohol. 
- Associated symptoms like fever, change in color of skin over feet, breathing difficulties. 
There may be following causes for swelling in your case - 
- Prolonged sitting. 
But other causes related to heart, Kidney, Liver disease need to be ruled out. 
Following investigation may help in diagnosis - 
- ECG, 2DEcho. 
- 
Complete Blood Count. 
- Renal function test. 
- Liver function test. 
- Urine examination including urinary protein. 
Depending upon clinical examination and above test results appreciate management can be planned. 
Hope this helps you, if so do vote as helpful.