Brief Answer:
investigation is required

Detailed Answer:
Hello,

if both feet are swollen then the most likely cause is a circulatory problem (defective vein valves). Other potential causes include (but are not limited to) the following:
- chronic heart failure particularly if you've been having swollen legs every so often or other symptoms like shortness of breath
- renal problems like proteinuria
- liver dysfunction with low serum albumin levels
- hormonal problems like uncontrolled hypothyroidism

Some of the aforementioned conditions may get worse when an individual stands or remains seated for too long.

Elevating the legs above the level of the heart may help to reduce the swelling.
The most sound advice would be to visit your doctor for assessment, clinical examination and testing. If the swelling is unilateral then the investigation should be carried out urgently.

I hope I've answered your question. Please let me know if you need further assistance.

Kind Regards,
Dr Panagiotis Zografakis
Internal Medicine Specialist

---