What are the signs that reveal your body's hydration level before you feel thirsty?

Many people believe that thirst is the only indicator that the body needs water, but the body sends other early signals that reveal hydration levels before reaching the stage of dehydration, according to a report published by Verywell Health. Among these signals is the stability of body weight throughout the day; losing more than 2% of body weight in a single day indicates fluid deficiency, while light-colored urine is a sign of good hydration, whereas dark urine suggests the need to drink more, with the caveat that certain medications and foods can alter its color. Good hydration also reduces dehydration symptoms such as thirst, dry mouth, headache, fatigue, dizziness, and poor concentration, and lowers the risk of kidney stones, constipation, and urinary tract infections, while adequate water intake improves energy, cognitive abilities, and mood. Some studies suggest improved skin hydration, but evidence for this remains limited. Water needs vary by age, activity level, and temperature, but an adult woman needs about nine cups daily and an adult man about thirteen cups, including fluids and food.