My son has had a swollen gland in the back of his head for about 3 years now. It developed when he was 6 months old. Nurse said it was from constantly having a cold and once cold season passed it should go down. He is now 4 years old and it still there and getting hard and now he is complaining about it hurting and giving him a headache. He was diagnosed with hyperreflexia and has experienced horrible moodswings in the last 2 years which we thought was just his age until we talked to the Dr's. Could the gland be a sign of something more serious? He gets sick easily, mood swings, hyperreflexia, sleep issues, screaming spells, headaches.....He had a sleep study done 2 weeks ago (waiting on results) and will have an MRI today.