How does dehydration affect sputum consistency?

Dehydration leads to a reduction in the amount of water available in the body, which in turn affects the consistency of mucus, including sputum. When the body is dehydrated, the mucus-producing cells in the airways produce less water content in the mucus. This lack of moisture causes the sputum to become thicker and more viscous, making it harder to clear from the airways. Thick sputum can complicate breathing and may lead to greater difficulty in clearing the airways, which could increase the risk of infection or respiratory complications. This is why the correct answer is that dehydration thickens the sputum.