What causes a tremor in 1 hand that always comes on in heat (like a hot shower) & at other times? its postural but also happens sometimes at rest - walking w hands by my side.intermittent. all blood work/mris clean. neuro unsure. only 29 & scared?

If neurologist does not detect the tremor and your brain MRI is normal you have nothing to worry. However, if tremor is also noted by the neurologist but he can't make a diagnosis, you should seek a second opinion. Take care and good luck!

A focal unilateral tremor would be secondary to a lesion affecting a focal area of the brain. For example, if the cerebellum has a small stroke, the tremor will be on the same side as the infarction. If your neurologist is "unsure", seek a second opinion.