What causes constant tiredness?
Its difficult to know exactly as your tiredness could be due to a number of things or none at all, for instance I suffered badly with low blood pressure and that left me light headed and constantly tired and even after a lot of sleep I still felt like I wanted to go to bed. It could be diabetes, tiredness is one of the classic signs of this or it could be you need folic acid or iron if your periods are heavy etc., Go to your GP for a blood test and see what happens, dont let this ruin your life when it could be sorted so easily. Good luck.