I have to take ciprofloxacin 500mg tab for 3days 1twice a day. But am feeling sick with lots of headech and nausia is it normal?

Yes. Nausea and headache are possible side effect of ciprofloxacin. It is important to know the cause of your illness for which Ciprofloxacin is prescribed. There is a possibility that nausea and headache could be the symptoms of your illness not adequately treated with Ciprofloxacin .