Although you cannot prevent the prostate from enlarging, you can take measures to reduce your symptoms:
Limit your intake of liquids in the evening, especially drinks containing alcohol and caffeine. Cutting back helps to minimize the number of times you have to urinate during the night. (Also, drinking too much alcohol may irritate the bladder or prostate. Most experts recommend that men avoid more than two alcoholic drinks a day.)
Ask your doctor whether you can change or eliminate mediations that may be aggravating the problem. These medications include antihistamines, diuretics, decongestants, antispasmodics, tranquilizers and certain types of antidepressants. These can weaken the bladder muscle or narrow the opening of the prostate.
Take every opportunity to use the bathroom and allow yourself enough time to empty your bladder completely.