[Aussie Girl]

Dear Colleen,

Sorry you are having this problem. Fainting is a fairly common symptom in the general community, sometimes in otherwise healthy people, although commoner in people with an illness that leaves them tired and weak. It sounds like you are getting the right work up to exclude any major problems.
Chemo causes anemia, gut problems that may cause dehydration, and can affect your nerves - not just in your hands and feet, but also the nerves that control your blood vessel dilation and therefore your blood pressure. Sometimes the drugs affect your heart which needs to be checked out. All of these things can cause fainting and will usually improve once chemo finishes.
So take care. Keep well nourished and well hydrated and avoid getting up quickly. Wearing support stockings that improve circulation of blood back to your heart may help. Sometimes you can work out what days of the chemo cycle are worse or what activities bring fainting on (eg. getting up quickly, coughing or straining on the toilet - increased abdominal pressure reduces blood flow to the heart).

Good Luck

Aussie Girl