Hello dear, In absence of any injury or trauma, the swelling in ankle can be attributed to either accumulation of fat (given the history that you are overweight) or fluid (secondary to Cardiac, Liver or Kidney disorder). Investigations like complete blood count, serum electrolytes, ECG, Lipid profile, Liver & Kidney function tests will be helpful in detecting any pathological cause for the symptoms. Regarding the problem of dozing off & fatigue, it can be due to: 1. Deficiency of certain nutrients like Iron, Vitamin B 12, Vitamin D, Calcium, etc. which interferes with blood formation & nerve conduction. 2. Any fluctuation in blood pressure & blood sugar levels. 3. Lack of adequate hydration & proper nutrition. So, it will be better to consult your General Physician & get a proper physical examination done to find out the exact cause. Based upon that, appropriate management steps could be taken. Meanwhile, maintain adequate hydration, take a healthy balanced diet & avoid stress. Wishing you a good health. Take care.