### Human:\nwhat is causing my extreme fatigue and weightloss? . i had a sudden onset of symptoms three months ago. i have constant fatigue from the minute i wake up to the minute i go to bed. over night i changed from being able to run for miles to struggling to get dressed without needing a lie down. struggle falling asleep but fine once asleep. body feels weak occasional leg numbness and i get muscle twitches in my legs and feet. i originally had lots of palpitations but not so much. i feel very spaced out. weightloss of almost a stone - any ideas why? .\n\n### Assistant: i have plenty of ideas but i do not know you your medical history or have any way of doing a thorough examination and diagnostic work-up. something that you need. you will need to see a medical professional. ideas are not diagnoses and there can be hundreds if not thousands of diagnostic possibilities that could account for your array of symptoms.