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.
Tea tree oil is poisonous when taken internally. It may cause drowsiness, confusion, hallucinations, coma, unsteadiness, weakness, vomiting, diarrhea, stomach upset, blood cell abnormalities, and severe rashes. It should be kept away from pets and children. Tea tree oil should not be used in or around the mouth.