How can i tell if i empty my bladder. i have to pee really bad but when i try i have to strain real hard?

Need either... or...: Subjective feeling not emptying bladder well cannot be always correct, but still suggestive; for confirmation, need checking residual urine right after voiding either with bladder scanning estimation or with direct catheterization. Remember: right skill and techniques of bladder scanning avoids wrong reading, and right skill in inserting catheter avoids discomfort. But, see doc to find out why...

UTI/stricture: If you are having pain while urinating than you probably have cystitis( lower uti), rx is antibiotic ; water. If you only have harder time in urinating (not painful) but the flow is slower and weaker then there might be narrowing of the urethra. ( can happen from previous infections) in either case you may have frequent urination, if symptoms persists more than 2 weeks , please consult your doctor.

See answer: Your symptoms are abnormal and i recommend you see a urologist for evaluation. Possible causes: hypotonic bladder, functional or anatomical obstruction; or a condition such as interstitial cystitis where you have the sensation of urgency, pressure, and a full bladder despite only having a few ounces of urine in bladder. A bladder scan or catheter insertion is required to check if bladder empties.