I have episodes of extreme/sudden tiredness that last from 30 mins to several hours, a few times a week. It usually happens mid-morning when I'm at work (in an office on a computer - but I've done that for many years). It's tiredness to the point that I feel like I've been drugged & find it almost impossible to stay awake, let alone concentrate. Sometimes I get light headed and/or nausea with it. I've recently had several tests (carotid artery doppler, brain CT, ECG & Electrocardiograph, pelvic US) and all clear except for sinus issues (sinus in the nose/face, not sinus heart rhythm).
Can anyone please help? If this keeps up, I may lose my job. Lisa.