I've been mugging up on orthostatic intolerance, which I'm going to be tested for this week. Some advice says that you should raise the foot of your bed, e.g. Dr Stewart writing about POTS: "Raising the foot of the bed at night can increase blood volume." Other advice says that you should raise the head of your bed, e.g. Dr Rowe says: "Another time-honored recommendation is to elevate the head of the bed slightly by 10-15 degrees, so that the head is higher than the feet, a position that appears to help the body retain fluid at night rather than lose fluid into the urine." Does anybody have any idea which it should be? The most common recommendation I've seen is to raise the bed head, though it seems counter-intuitive. I mentioned it to my (non-specialist) doctor and he didn't know what the physiological mechanism would be for it to work. A secondary question: I can't tilt my whole bed because of how it is constructed so I'm getting a wedge that goes under the mattress that will tilt the upper (or lower) half of the mattress and therefore my body at 15 degrees. Does anyone know whether that's likely to be sufficient? According to my geometry calculations, raising the whole bed to a 15 degree tilt would require you to raise a six-foot bed by one and half feet, which seems a lot!