Balancing chemical equations is a key chemistry skill. Use these step by step instructions to write and balance chemical equations. Balancing chemical equations is a key chemistry skill. Use these step by step instructions to write and balance chemical equations.
So, there are many signs and symptoms of Selenium Overdose- some occur very early and some occur much later. 1  Early Signs: Some of the early signs of Selenium Toxicity are endocrine hormone disturbances- particularly thyroid issues. Poor hair and nail growth are early signs that are probably the easiest to notice.
The following are some common symptoms of overdose: 1  Blue or yellow skin. 2  Confusion. 3  Fever. 4  Less frequent urination. 5  Weakness. 6  Numbness or swelling. 7  Vomiting or nausea.