Note: This article is for educational purposes only and is not intended to provide any Fall/Winter Check-in Challenge medical advice. 
Why do lips get dry in winter?
The answer lies in the unique anatomy of the lips. The lips are thinner compared to the rest of the face, which makes it more susceptible to dehydration. The ** tissue of the lips resembles the mucous membranes inside the mouth, consists of only three to five layers of tissue, and does not contain any hair follicles or sweat glands found elsewhere on the face.
In fact, the ** cell layer on your face is six times thicker than the cell layer on your lips, and your lips also have fewer oil glands compared to the rest of your body.
In winter, the outdoor air becomes colder and less humid, and people turn on heating and air conditioning in their homes and offices. Constant exposure to dry air can dehydrate the delicate ** of the lips, causing them to crack, flaking, and bleeding.
While people are tempted to alleviate it by licking their lips, this can actually exacerbate the problem. This is because saliva contains digestive enzymes such as amylase (which breaks down starch into sugars) and lipase (which helps in the digestion of fats).
When you lick your lips, dry saliva removes the natural oily protective layer that helps keep your lips healthy, and over time, these enzymes can damage the lips** themselves and cause dehydration.
Chapped lips can make them more susceptible to infections that penetrate the barrier. According to a review published in 2018 in the journal Croatian Clinical Journal, microorganisms such as Staphylococcus aureus or Candida albicans may exacerbate lip inflammation and thus worsen symptoms.
If chapped lips don't improve after using lip balms, ointments, or humidifiers, it's best to see your doctor.