How is the arm muscle beating?

Muscle beating is actually caused by the contraction of a group of muscle cells, which is called muscle bundle tremor in medicine. This muscle tremor can have different areas and amplitudes, some small tremors can be felt but not seen, and the more obvious tremors can be seen by the naked eye. Muscle beating is usually benign if it is not accompanied by muscle weakness and atrophy. Most benign muscle beats can't find the exact reason. It may appear when you are tired or stressed, and drinking tea or coffee may also aggravate this beating. Most of these beatings are intermittent, but a few people may easily occur frequently due to physical factors. This situation is similar to eyelid flutter, in fact, eyelid flutter is also a benign muscle tremor.

Guiding opinions:

There is no need to worry too much about this situation. Generally, it will disappear on its own under the condition of reasonable diet, guaranteed sleep and relaxed mood.

I suggest you find an acupuncturist to do acupuncture, massage and massage, or you can fry salt and heat the affected area.