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Swelling in ankle can be a result of fluid retention,due to Systemic diseases.
Other possibility is of disease related to joints.
The common causes are- Liver /heart or kidney disease , Nephrotic syndrome and Arthritis, Gout, Lymphatic obstruction.
To make a diagnose you require blood work and detailed clinical checkup.
Test includes-
Liver function test, Kidney function test, Complete blood count, EKG, Ultrasound of legs.
You will be treated according to the cause.

A clinical examination and tests are necessary for diagnosis. Medications will be prescribed after clinical evaluation.
Please make an appointment with doctor for management of this issue. Good luck and take care.

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