Hi More details are needed. Does he have fever every time? Did he have any breathing difficulty when he was admitted? Does he require antibiotics every time? Do you send him to any daycare? Do you have any elder kid in the family who brings infections from school? How is his weight gain? If he is gaining weight and there is no weight loss, you need not worry much. - If associated with fever every time, it suggests infection- viral or bacterial. This happens more in kids left in day care or when the elder sibling attending a school brings home the infections. In such a case, give him nutritious food, fruit pulps, vegetable soups, boiled vegetables etc. You might ask your Pediatrician for micronutrient supplementation . If he is on breastfeeds, continue to feed him. And who ever handles the baby should wash hands properly each time they handle him. - If there is no fever each time, it might be allergy/ asthma. Kids might be allergic to pollen, dust, animal danders, perfumes etc and if possible exposure to such things should be avoided. Medications are available to prevent such allergies- your doctor might help you with this. Hope my answer helps you. Wish your kid good health!