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.
1 Using large quantities of tea tree oil on the skin could cause severe side effects.  For topical use only. Tea tree oil must never be used in the eyes or swallowed. Even in small amounts, swallowing tea tree oil could potentially cause severe reactions, including severe rash, nausea, confusion, and coma.