What Causes Swollen Glands In Throat?

Hi, I've had a scratchy sore throat for 2 days, dry cough, and today I noticed swollen glands, and the veins under my tongue are swollen and very blue. I feel a little short of breath of late, but then have been in Bangkok and Kuala Lumpur smog, I also have asthma so have use my inhaler a couple times, which seemed to help, I bad sinus type headache for a few days also, it has subsided since taking antihistamine. What can cause the vein swelling. I take thyroxin daily, have had some weight gain due to not watching my diet (in the middle of an international move). Any assistance is appreciated.