<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing focal weakness in my hand, along with a lump and muscle stiffness. Also, my hand and finger hurt a lot.  <response>: Based on your symptoms, it seems like you have injured your hand. The lump could be a result of swelling or a fluid-filled cyst. I would recommend getting an X-ray and an MRI to assess the extent of the injury. 