• There are difficulties with the terms used to describe lower urinary tract symptoms in men.
• Terms such as 'prostatism', 'symptoms of benign prostatic hyperplasia', and 'clinical benign prostatic hyperplasia' have been used to describe lower urinary tract symptoms in men. However, because different symptoms require different approaches to treatment, and the prostate is only sometimes a causal factor in some of the symptoms, this terminology is inaccurate and can be unhelpful in guiding management [Abrams, 1994].
• Alternative terms have therefore been proposed. The National Institute for Health and Clinical Excellence (NICE) recommends that the term 'lower urinary tract symptoms (LUTS)' be used instead of the terms 'prostatism' or 'symptoms of benign prostatic hyperplasia' [NICE, 2010].
• NICE does not recommend that the term LUTS be used in place of 'benign prostatic hyperplasia (BPH)' — LUTS refers to a set of symptoms, while BPH refers to a condition.
• NICE does not suggest that LUTS is a synonym for symptoms of BPH — LUTS includes symptoms of BPH, but also includes symptoms due to other causes.
• Lower urinary tract symptoms can be grouped according to their physiological cause.
• Storage symptoms include urgency, daytime urinary frequency, nocturia, urinary incontinence, and feeling the need to urinate again just after passing urine.
• The term storage symptoms is preferred to the commonly used alternative terms, irritative symptoms and filling symptoms, because it indicates that the cause is a functional abnormality and not a structural problem or inflammatory process.
• Voiding symptoms include hesitancy, weak or intermittent urinary stream sometimes causing splitting or spraying, straining, intermittency, incomplete emptying, and terminal dribbling.
• The term voiding symptoms is preferred to the commonly used alternative obstructive symptoms, because it indicates that the cause is often due to detrusor underactivity and not mechanical bladder outflow obstruction.
• Post-micturition symptoms include post-micturition dribble, and the sensation of incomplete emptying.
• Benign prostatic hyperplasia is the condition in which biopsy of the prostate shows histologic signs of hyperplastic changes (abnormalities at the cellular level). Only a quarter to a half of men with benign prostatic hyperplasia have LUTS, and often the predominant problem is voiding symptoms.
• Benign prostatic enlargement describes enlargement of the prostate gland by benign prostatic hyperplasia. Only about half of men with benign prostatic hyperplasia develop benign prostatic enlargement.
• Bladder outlet obstruction is diagnosed when urodynamic voiding studies show increased detrusor (bladder wall muscle) pressure and reduced urine flow rate.
• Lower urinary tract symptoms suggestive of bladder outlet obstruction indicates that the man's main complaint is of voiding symptoms in the absence of infection or obvious pathology other than possible causes of outlet obstruction. This term should be used until bladder outlet obstruction is confirmed by urodynamic studies, because only around 40–60% of men with LUTS suggestive of bladder outlet obstruction are confirmed to have bladder outlet obstruction when tested [Belal and Abrams, 2006].
• Overactive bladder is a syndrome (symptom complex) of storage symptoms: urinary urgency, with or without urgency incontinence; frequency; and nocturia. Both stress incontinence and overflow incontinence are excluded from the definition of overactive bladder. Overactive bladder symptoms are usually caused by bladder (detrusor) overactivity, but can be due to other forms of voiding dysfunction.
• Detrusor overactivity is diagnosed when urodynamic studies show involuntary detrusor contractions during the bladder filling phase. Detrusor overactivity occurs in approximately two-thirds of men presenting with overactive bladder symptoms and half of men with bladder outlet obstruction.

[NICE, 2010]