Hi there. This condition is called Micturition Syncope. Please visit your Doctor for detailed examination. Please Avoid excessive drinking of alcohol. Don't get out of bed suddenly — first, sit on the edge of the bed and move your legs, making sure you aren't dizzy or lightheaded Urinate sitting down. As much as possible, ensuring the floor from your bed to the bathroom is carpeted or padded also is a good strategy for avoiding injury from a potential fall.