What Causes Nausea And Dizziness Post Workout?

My son worked out and afterwards went jogging at the park that night he developed nausea, his left arm was hurting, he was dizzy, couldn t sleep. Went to the clinic they told him his hemoglobin was high. He has been drinking a lot of fluids, now three days later he did one hour of workout and symptoms return. He needs to teach Zumba tomorrow and he doesn t know what to do, what is the treatment?