Doctornee has provided an excellent list of possibilities.
That being said, the most common etiology is diabetic neuropathy.
You need a diabetic screen consisting of a test called the hba1c and either a fasting glucose test or the insulin clamp protocol to determine your diabetic status.
This screen is relatively inexpensive, and in the United States is free at many clinics.
Hi
Welcome to the MedHelp forum!
Numbness of the big toe can be due to pinched nerve, poor circulation, faulty foot wear, diabetic neuropathy, leprosy, nerve injury, multiple sclerosis and frost bite. This needs to be investigated before a final cause can be pin pointed. Take care!