Medicine is a highly competitive subject. According to UCAS, in 2010 there were 21,389 applications to medicine and only 8,009 were offered a place and started in Septemner 2010.  

Good academic qualifications are normally required because the course is long and intellectually demanding. Although applicants may also be selected based on other criteria, e.g. skills and attributes.
 
If you do not have the required grades and are not eligible for any of the foundation or widening access courses you may wish to consider other alternatives. These may include subjects allied to health or a science degree.

The Medical Careers website has a careers planning section which may be helpful. Your local careers advisor should also be able to advise you whether you have the right skills and attributes to study medicine.