Manipulation of the spine, and especially of the cervical area, can be dangerous. If the neck is twisted too far, it is possible to tear the walls of the vulnerable vertebral arteries where they pass up to the neck. The result can be an aneurysm or blood clots, which, in turn, can cause a stroke or other neurological symptoms, such as vertigo and slurring, or even be fatal. 

There have been cases of neurological damage following chiropractic manipulations of the neck. In 1992, researchers at Stanford Stroke Center found that 55 people had been referred to neurologists in California following manipulation. They were suffering from permanent nerve damage, and one died. The vast majority of chiropractic manipulations are safe, but any manipulation carries a risk, so it is important that it is not undertaken lightly or unnecessarily. 

The spine should never be manipulated if there are any signs of a neurological involvement, such as a loss of sensation in the legs or impaired bladder control. Bone diseases, such as osteoporosis or cancer, a recent fracture, or serious circulatory problems, such as aneurysms or a history of thrombosis, are also contraindications for the use of spinal manipulations. If in doubt, consult your doctor. 

Chiropractic is not recommended for disorders of other than musculoskeletal origin, and should be avoided for certain musculoskeletal problems as well. For in- stance, it is not recommended for osteoporosis, bone or joint infections, bone cancer, acute rheumatoid arthritis, and diseases of the spinal chord or bone marrow. It should also be avoided in an area that has been operated on, such as a spinal fusion, and near acute fractures and dislocations or healed fractures and dislocations with signs of ligament damage. Chiropractors do not treat fractures. 

Scoliosis, a condition in which the spine curves to the side, is generally considered a target for chiropractic therapy. However, idiopathic scoliosis, which develops over time instead of being present at birth (congenital scoliosis), is not appropriate for treatment by a chiropractor.