Dryness of mucous membranes in newborns

Dryness of mucous membranes in newborns: Indicator of dehydration

The condition of the mucous membranes of the oral cavity and eyes is a simple and accessible indicator for parents of the child's hydration status. In a healthy, well‑hydrated newborn, the mucous membranes are always moist and glossy. Their dryness is one of the early and obvious signs of dehydration.

Why do mucous membranes dry out first?

The mucous membranes of the mouth and eyes are constantly bathed in saliva and tear fluid, which are 99% water. When the body begins to sense a fluid deficit, it activates compensatory mechanisms. One of the first steps is to reduce the production of fluids that are not vital at the moment, namely saliva and tears. The body tries to conserve water to maintain blood volume and internal organ function, "sacrificing" mucosal moisture.

How to check?

Parents can easily assess this symptom:

• Lips and tongue: Lips become dry, cracked. The tongue may be covered with a white coating and appear "rough". When touching the inner surface of the cheek, the finger feels stickiness rather than moisture.
• Crying without tears: This is a later but very characteristic sign. In newborns, tears may be absent in the first weeks, but if they were present and then disappear during illness — it is a warning sign.

Dryness of the mucous membranes usually appears with mild to moderate dehydration. If this symptom is combined with decreased urine output, it is a clear signal to act.