Hand pain from writing is a common issue often caused by muscle overuse, poor grip, or improper posture. It can also be a symptom of conditions like "writer's cramp" (a form of focal dystonia) or repetitive strain injury (RSI). Other contributing factors can include holding the pen too tightly, using a pen that is too thin, or not taking frequent breaks. Proper hand and wrist ergonomics, using an ergonomic pen, and performing stretches can help alleviate discomfort and prevent long-term issues.