Mild trembling of the thumb and fingers can occur due to stress, anxiety, tiredness, excess caffeine, poor sleep, weakness, vitamin deficiency, thyroid imbalance, nerve-related conditions, or early movement disorders. In many people, the shaking becomes more noticeable during stress, holding objects, writing, or when the hands are tired. A neurologist is usually the most suitable specialist if the trembling keeps increasing, affects daily activities, or continues for a long time. Blood tests for thyroid function, vitamin B12, blood sugar, or nerve-related evaluation may sometimes help identify the cause more clearly. Reducing stress, improving sleep, limiting excess tea or coffee, proper nutrition, and regular exercise may also help if the tremor is stress-related. Sudden worsening shaking, stiffness, weakness, difficulty walking, slurred speech, or tremors affecting both hands continuously may suggest a more significant nerve or movement-related problem and may need further neurological assessment.