For thousands of years, marijuana has been used for medical reasons ranging from a reliever for earaches, child pains as well as stress. It can be traced all throughout Europe, Asia, Africa, and the Middle East.

Medical research recently has also unearthed in the past decade marijuana's effects on various kinds of pains. These range from damaged nerves in people that have HIV, diabetic treatment, and spinal injuries--marijuana has also shown promise to patients with cancer and Multiple Sclerosis.

The use of medical marijuana has also been speculated to aid with nausea induced by chemotherapy, and with extreme loss of appetite in patients with AIDS.

THC is an ingredient in marijuana that mimics the action of chemicals that naturally occur in the brain. The tetrahydro cannabinol (THC) activates receptors in the body's nerves that trigger physiological responses in the brain.

The only legal extract of THC currently available is Marinol however the results are not evn close to the effects of naturally smoked medical marijuana. Taken orally, its absorption is highly variable and unpredictable and often delayed, says Dr. Igor Grant, a UC San Diego psychiatrist who directs the university's Center for Medicinal Cannabis Research. "Smoking is a very efficient way to deliver THC," he mentions.

Medical marijuana is considered illegal under federal laws, so its only available is selected clinics in states such as California where they have passed laws making marijuana legal for personal medical use.

Currently, the only research available is provided by the government that issues various potency of marijuana cigarettes that they supply to the National Institute on Drug Abuse (NIDA).

The UC Center for Medicinal Cannabis Research in San Diego, California helps coordinate clinical studies to delve into the safety and efficiency of medical marijuana and they've gathered studies related to neuropathic pain, Multiple sclerosis, and nausea.