need help,need answer... about fainting?

My sister in law has been faintng for months now and she has been to the hospital tons of times.  She faints and she is unconcious for hours.  When she awakes she feels really weak and she gets migrane (migraine). The doctor's have done tons of test and they cannot tell her the cause of this.  The family is desperate and we donot know what to do.  She faints 3 to 4 times aday.  She has fainted and hit her head most of the time she falls.  Can anyone tells us what to do? We are desperate!!!!

[drrajgopal18]

Hi,
Fainting or syncope occurs due to decreased blood flow to the brain . Decreased blood flow to the brain can occur because 1) the heart fails to pump the blood; 2) the blood vessels don't have enough tone to maintain blood pressure to deliver the blood to the brain; 3) there is not enough blood or fluid within the blood vessels; or 4) a combination of reasons one, two, or three above. More precisely the causes of fainting are – Heart rhythm changes ,  Structural changes in the heart or valves , Postural hypertension,  Vasovagal  syncope , Anaemia, dehydration , Orthostatic hypotension , Electrolyte imbalance  and pregnancy .  Please consult a cardiologist for the diagnosis . For complete information regarding fainting , please go through the site - http://www.medicinenet.com/fainting/article.htm . Hope this helps you . Take care and regards !