@ysmina-- I know about that. It happens to my dad sometimes. When he first started seeing swelling in his forehead, he though it was neurological or related to an infection. He had several tests done and the doctors didn't find anything. He also didn't have a sinus infection or anything similar.
The doctors finally linked it to migraines because the migraines and swelling always occurred together and never separately. It was a relief to know that the cause wasn't something more serious.
My uncle had a bad case of forehead and face swelling for about a week last year too but his was because of his hair transplant surgery.