Urination is not as strong as it used to be, and in men it is most commonly a symptom of prostatitis and prostate enlargement. Prostatitis is the most common disease in young men, and weakness to urinate is the most common symptom of prostatitis. This is because in patients with prostatitis, prostatitis causes narrowing of the posterior urethra and poor urine flow during urination, so they will urinate weakly. And in older men with prostate enlargement, it is often just an increase in nocturnal urination, thinning of the urine line, bifurcation of urination, and weakness of urination which are the most common symptoms of the disease in older men. In women, weakness to urinate is most often a symptom of infection and bladder neck enlargement. Another thing is bladder frequency, such as when bladder neck enlargement causes obstruction of urination, so you can urinate weakly. When you have an infection, you have frequent, urgent and painful urination, and then you have incomplete urination, which is weakness of urination.