Can tremors come and go?

Yes : Stress and coffee may make worse, alcohol and sedatives and/or relaxation may make far better. Some medicines may cause tremors.

Hand tremors: Hand tremor is likely a manifestation of benign essential tremors, usually more prominent in one hand, commonly hereditary, worse with caffeine use, stress and activity. It is a fast frequency low amplitude tremor. It may not be noticeable when calmed or relaxed. Responds to medications like Propranolol or primidone. Tremors could be due to other conditions. Check with your doctor for correct dx.

Depends: Depends on what the cause of the tremors is. Yes they can be intermittent.

Tremor: A tremor is a repetitive movement of a part of your body. It is involuntary. This means that it is generally not controllable and happens without you deciding to move that body part. It is often felt as a trembling or shaking sensation. http://patient.info/health/essential-tremor http://patient.info/doctor/tremor-pro