Hi welcome to the health care magic According to history respiratory causes has to be ruled out.... Your leg calf muscle has to be examined and if red and swollen than venous thrombosis has to be ruled out by doppler and pulmonary embolism searched for by D dimer estimation... Your Auscultation has to be done and chest x ray done... It will guide further management plan.. According to cause further specific treatment given If needed throat swab taken and send for influenza examination and if needed antiviral drug prescribed like oseltamivir.. Take care Hope your concern solved Consult pulmonologoist for examination and further work up done accordingly