Doesn't matter. Some doctors say bacteria is the cause, some say stress, some don't have a guess. But all of these doctors will have a "CURE". The truth is, none of them have any cures, they just have poisons that make one pain go away and two new ones take it's place. Firstly, ponder anything that can be percieved as a poison or toxin. When you shower, the contents of what you put on your skin is absorbed through your skin, think chlorine, fluoride, lead, mercury, contents of soap and so on. Next, think about the bed sheets and pillows, carpet, clothes. Now imagine nearly invisible particles of polyester being inhaled in large volumes from these sources. Drink 32oz of freshly pressed organic juice, up to a gallon if unwell. You need to get all bio-available minerals, vitamins, amino acids (this is what makes up protein which can be find in vast volumes in places other than meat) and essential fatty acids. Eliminate all foods that aren't whole, organic and natural. Then start to develop and study what makes a good diet.