What causes clenched fist?

A clenched fist can be caused by various factors, including physical exertion, emotional responses like anger or frustration, or neurological conditions such as Parkinson's disease. It may also occur as a result of muscle tension or stress. In some cases, a clenched fist is a natural reflex or protective response to perceived threats. If it happens frequently or is accompanied by pain, it may be advisable to consult a healthcare professional.