Hit on top of head while boxing 7 days ago. it is hard to concentrate & headache worsens when i shake my head. how long do these symptoms linger?

Concussion: Sounds like a concussion. The symptoms you describe can last 4-6 weeks. If you have not seen a doctor, I would recommend getting an evaluation.

Concussion: Important to see your doctor about this, as a baseline workup is indicated, and you still plan on boxing. Your answer is that for athletes it usually takes 4 weeks to improve, and mental and physical rest are recommended. Non-athletes can have symptoms for 6-8 weeks. But a doctor workup is essential.