Normally nothing much happens after blood donation
but some people may feel tired or dizzy after the donation.There is nothing much to worry about.
You are asked not to do any strenuous activity or lifting of weight for 12 hours after the blood donation.
Take plenty of water and juices to keep yourself hydrated well.
Your body replaces all the fluids donated within 48 hours and all your red cells are replaced within 4-8 weeks.
You might have done some strenuous activity after the donation which might have caused these leg cramps