Drink plenty of fluids, such as water or juice. This will help dilute mucous secretions and promote drainage. Avoid beverages that contain caffeine or alcohol, as they can be dehydrating. Drinking alcohol can also worsen the swelling of the lining of the sinuses and nose...Bacteria, viruses, or fungi in pool water can enter the nasal passages, which can lead to inflammation and even cause infections. Chlorine, however, is an even more common cause for post-swim sinus problems. The chlorine in pools can cause inflammation in the lining of the sinuses causing you symptoms....for prevention use nose clips and to use a saline spray or saline nasal irrigation system after your swim session...Consult ent surgeon for further details.