Is milk or other drinks except regular water considered as hydration?example,when you drink 8 glasses of water& a glass of milk,can that cause overhydration?is it considered as 9 glasses of water for hydration or just 8?idk how to explain this?

While there are a lot of solids in milk, the majority of the volume is water and contributes to the overall daily volume of water you need to keep your body hydrated and your kidneys working properly. The solids in milk are food.

You could replace water with milk for hydration, however, milk has fat and calories and could add to your weight in an unhealthy way. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV, Flu and Covid vaccines. Wish you good health!