「沒事多喝水，多喝水沒事」是一句深植人心的廣告台詞，但多喝水真的無害嗎?答案並不盡然，至少，對於膀胱過動症的朋友，多喝水反而會加劇膀胱過動症的症狀，增加頻尿及尿急感的嚴重程度，嚴重降低生活品質。對於膀胱過動症的治療，目前第一線治療方法其實不是吃藥，反而是生活習慣的調整，而「喝水量」就佔有舉足輕重的地位，目前大多建議膀胱過動症的朋友一天喝水量不要超過2000cc，但很多人心中會產生疑惑，減少喝水量，難道不會對身體造成影響嗎？今天跟大家分享這篇文章就是為了解開大家心中的疑問。這篇文章針對1972年到2017年間選出和喝水量相關的醫學論文共47篇進行分析，包括飲水量和膀胱過動症，尿路結石，心血管疾病，便祕，靜脈血栓，頭痛，認知功能，以及膀胱腫瘤的關係。結果顯示，喝水超過2000cc只有對於尿路結石的防治有顯著效果，但對於其他疾病，包括：心血管疾病，便祕，靜脈血栓，頭痛，認知功能，以及膀胱腫瘤並無明顯的幫助。同時本篇文章更指出，有小規模的研究報告顯示，膀胱過動症的朋友如果減少25%的液體攝取量可同時降低 23%頻尿，34%尿急感，以及7%夜尿的嚴重程度。儘管這些數據還需更多大規模的研究佐證，但也讓我們了解飲水量和膀胱過動症的息息相關。總而言之，一天喝水量不要超過2000cc，除了可以有效降低膀胱過動症的惱人症狀，同時不會對人體造成負擔 (除了同時有尿路結石者)，請膀胱過動症的朋友們不要擔心。

Purpose: Overactive bladder imposes a significant socioeconomic burden on the health care system. It is a commonly held belief that increased fluid intake (8 glasses of water per day) is beneficial for health. However, increased fluid intake exacerbates overactive bladder symptoms. Thus, it is imperative that clinicians appropriately educate patients for whom increased water intake may be detrimental (women with overactive bladder), in contrast to patients with comorbidities that necessitate increased water intake (nephrolithiasis). We systematically reviewed the literature to determine the potential health advantages of increased water intake and identify specific subpopulations that need increased hydration.

Materials and Methods: We systematically reviewed published articles from 1972 through 2017 on PubMed_ and the Cochrane Library. The data were reviewed independently by 2 individuals. Studies were included if they explored water intake in relation to the risk of a particular disease.

Results: Level 1 evidence supported increased fluid intake in patients with nephrolithiasis. There was no available evidence to support increased fluid intake in patients with cardiovascular disease, constipation, venous thromboembolism, headaches, cognitive function or bladder cancer. Dehydration may exacerbate some conditions, specifically chronic constipation and headache intensity. Increased fluid intake may have a role in preventing stroke recurrence but not in preventing primary stroke.

Conclusions: The available reviewed literature suggests no benefit to drinking 8 glasses of water per day in patients without nephrolithiasis. Also, excess fluid intake can exacerbate symptoms of overactive bladder.