Could these symptoms be an allergy, perhaps hayfever,as they seem to be worse on mild weather days.

1. Muggy Head
2. Headaches
3. Tiredness
4.sneezing (not alot but more than is normal)

Thx for any input, as I just don't know what it is. I have tried a antihistamine, whcih may have worked slightly, but not enough to give any great relief.

it most definitely be allergies. With Spring in almost full swing.. it could be the budding trees/blooms etc. I use zyrtec and nasonex when it gets bad. I have also been using a neti pot to irrigate the sinuses..helps wash out any allergens