Ok i am a high school track runner and have hamstring pain every time when i run full speed it hurts but when i jog i'm fine i have had it for 4 weeks?

Exam/imaging: You may have small micro tears in the hamstring muscle due to previous severe muscle pull or injury. Certainly get examined, use a hamstring support and over the counter antiinflammatory meds, If this continues, you may benefit form an orthopedic evalaution and possible imaging.

Ham strain: You have a tight hamstring group. Strain or sprain happens with Full speed. Warm up more, stretch more, get trainer massages.

Ask the coach.: Running puts a strain on the hamstrings and can even cause a rip. jogging is better but ask your coach or see a sports medicine doctor