How long does it take to completely dehydrate? Factors and Risks Explained
                                
                                
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                                    5 min read                                
                            
                                The human body is composed of over 60% water, making it critically dependent on hydration for all metabolic functions. So, how long does it take to completely dehydrate? For the average person, a dangerous state of severe dehydration can set in within 3 to 5 days without fluids, though this is highly variable.