A person can generally survive without water for about 3 days, though this can range from 2 to 7 days depending on various factors

. Dehydration progresses rapidly, causing symptoms like extreme thirst, fatigue, and eventually organ failure and death within this timeframe

. Factors influencing how long someone can go without water include:

• Environmental conditions (heat, cold)
• Physical activity level
• Age and overall health
• Body weight and fat composition
• Sex
• Food intake (some foods contain water)

For example, in hot climates or with heavy exertion, survival without water may be as short as a few hours to a couple of days due to rapid fluid loss from sweating

. Conversely, sedentary individuals in cool environments might survive slightly longer

. There are rare documented exceptions, such as an 18-year-old Austrian who survived 18 days without water under extreme conditions, but these are extraordinary outliers and not representative of typical human limits

. In summary, while the average survival time without water is about three days, individual circumstances can cause this to vary significantly, but survival beyond a week without water is extremely unlikely