Hi thanks for asking question. You can have repeated viral infection.If you are not taking care in taking proper nutritional diet with fruits then your immunity not maintained well and chances of repeated infection. So take more fruits esp.citrous fruits rich in antioxidants along with more water. If you have habit of smoking then stop it, as it can lead infection by bronchitis or sore throat repeatedly. Second in your working area you might have allergy to specific substance or food might be pollen , chemical etc.Try to find that allergen if possibility.allergy test can be done. While infection get your CBC that if reveal eosinophilia allergic will be cause and if lymphocytosis mostly viral will be cause. Try to maintain immunity with adequate sleep. If still cause not clear symptoms for other diseases has to be searched ex.HIV or any other disease by history and physical examination. Drug history also taken meanwhile. Wish you good health