A headache refers to a nervous system disorder in which you experience pain in your head regions starting above the eyes and ears as well as the back of your head and upper neck. While headaches are common under no circumstance should they be taken lightly. Severe and chronic headaches warrant a visit to the doctor as they could be an indication of something serious. There are some things that can aggravate a headache. Here are things that you must absolutely stay away from if you have a headache. Air conditioning: Love sleeping with the AC on the whole night? When the AC is on the temperature