Yes when i stand up my blood pressure goes down a little bit and more than one time my blood pressure it was a little bit low but still in the normal average and i feel that the blood goes down to my feet and i feel tired even if i stand up a little bit

Probably normal: Orthostatic (when you stand up) change in your blood pressure is normal. The blood does temporarily pool in your legs and the decrease flow of blood to your heart leads to a temporary drop in your blood pressure. Try to avoid suddenly standing or going directly from sleep to standing. Also, be sure to see you doctor for a full check up.