So generally in India they told you, you should not put your head to the north and sleep. [...] Suppose you are anemic and you go to your doctor what does your doctor prescribe for you? Iron. So an important ingredient in your blood is iron. If you put your head to the north and sleep during the night when you, when you are in horizontal positions then slowly the blood will get pulled towards your brain. When there is too much circulation in the brain you cannot sleep peacefully. It will keep you disturbed; "demons" will bother you. It won't let you sleep. If you have any kind of, you know inherently weak aspects in your brain or if you are of old age you could die in your sleep. One can have hemorrhage because extra blood is trying to enter the brain where the blood vessels are hair like. Something extra is being pushed because of the magnetic pull. When you are in a vertical position this is not so. The moment you become horizontal this pull on the head is so strong that slowly the blood tries to move towards the brain. So to avoid this, this is true only in the northern hemisphere. If you go to Australia you should not put your head to the South. If you are in India you should not put your head to the North....
- Jaggi Vasudev (in this YouTube video)
...your grandmother used to say you shouldn't put your head to the north...they didn't have any scientific explanation back then...but the scientific explanation is, the magnetic field goes from North to South. If you put your head to the North, the magnetic current passes right through your body, so you feel weak and tired when you wake up. Your sleep is not complete.
- Ravi Shankar (in this YouTube video)
There was a NASA study titled Electromagnetic Field Interactions With The Human Body: Observed Effects And Theories, but I'm not sure if it's related to what these guys are saying.
So, does Earth's magnetism really have any effect on us especially when we are sleeping?