Left-thumb-twitching-meaning -

Most cases of thumb twitching are triggered by daily habits or physical strain:

Repetitive movements from texting, gaming (often called "gamer's thumb"), or typing can strain thumb muscles and deplete the electrolytes they need to function.

As a stimulant, high amounts of caffeine can over-excite muscles throughout the body, including the thumb.

A lack of essential minerals—specifically magnesium, calcium, or potassium —can disrupt normal nerve and muscle signals.