It usually starts in the nerves farthest from the brain and spinal cord -- like those in the feet and hands. Then it may move up into the legs and arms. However, if you get treatment for the medical condition causing the nerve damage, you may be able to stop the damage -- and even reverse it.
If swallowed, tea tree oil can cause varying side effects ranging from drowsiness, upset stomach, vomiting, nausea and weakness, to coma, hallucinations, blood cell abnormalities, confusion and ataxia which affects muscle coordination and your ability to move voluntary muscles, states the American Cancer Society.
Hormonal Side Effects. One troubling side effect of tea tree oil is the possible hormonal side effect on young boys who have not yet started puberty. Tea tree oil used at this age may cause problems with increased production of breast tissue in boys in a condition known as prepubertal gynecomastia, states the National Institute of Health.