Your piercing site has gotten infected which will cause swelling pain and redness around the area. If you are wearing artificial stud then change to gold as it is inert or use a plastic thread. Since the nose and upper lip area is considered the dangerous area of the face for infections to spread, take immediate treatment before your infection spreads or worsens. Antibiotics and local antiseptic cream will help. Removing your piercing will help but the hole may close if left for too long.

the piercing site has got infected..start antibiotics and local antiseptic..if no improvement remove the pierced object.

Pain and swelling after nose piercing is usually due to infection. You need to remove the nose stud for few days and take antibiotics, painkillers and apply antibiotic ointment for few days for faster recovery