What causes pain on left side of face and dizziness while running?

Brief Answer:
Probable primary exertional headache.

Detailed Answer:
I read your question carefully and I understand your concern.

Judging from that immediate onset in the setting of physical exercise the most probable diagnosis is primary exertional headache. It is a type of headache occurring during exertion which can last from 5 minutes to 48 hours. Primary means that no cause can be found. It is a benign type of headache.

However, there are the rare cases when the headache may be related to a brain lesion such as a bleed. I don't want to scare you by saying that, the probability of that being the cause is very low, but especially if the headache persists and this is the first time it has happened, a physical exam by a doctor is recommended to check for neck rigidity or other neurological signs.
Also blood pressure management is necessary as nose bleed at times can be related to high blood pressure (again unlikely at her age, just to make sure).

As for the concussion I don't think it is related if she had been feeling well.

I remain at your disposal for further questions.

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