Dear Doctor, My lips are always dry. Regardless of the fact that I take plenty of water eventually they dry up and people think I am dehydrated. What could be the problem? Nathan Dear Nathan, Dry lips are indeed troublesome. They look bad aesthetically and feel uncomfortable. Eating hurts if spicy food comes in contact with the lips, drinking hot liquids can hurt it and even speaking can become painful. Moreover there is risk of secondary bacterial infection setting in causing painful boils. The most common cause of dry lips is exposure to dust, wind or sun as that tends to deplete lips of moisture. On feeling dry, one tends to smack the lips to remove dryness. But this further tends to deplete the moisture and excess smacking of lips can cause dry and cracked lips. It can also be due to dehydration when body loses excess fluid. Mouth breathing tends to deplete moisture of lips causing cracks and fissures to appear. Viral infections like angular cheilitis manifest as cracks and fissures in side of lips. Metabolic disturbances like hypothyroidism can cause over all dryness of the body and even chronically dry lips. It can be due to allergy to something applied over lips like a lip balm or lipstick. Studies have shown that sodium lauryl sulphate used in tooth pastes can also lead to dry and cracked lips. Deficiency of vitamin B complex also leads to dry skin and lips. Drugs like propranolol used for hypertension or Accutane used for acne and some anti allergy drugs can cause dry lips. Apart from all other conditions, it can be due to genetic factors as well. Drink more water, keep face and lips clean. While going out in sun try to use sunscreen over lips as well. Avoid lip smacking. A diet containing adequate amounts of vitamins B complex group is useful. This means eating whole grains, nuts, fresh fruits and vegetables. Drinking more water keeps lips and body well hydrated and avoids chapping. Try changing to another type of toothpaste that does not contain sodium lauryl sulphate. Use of protective lip balms and Vaseline helps to prevent and treat cracked lips. If the condition persists, it is advisable to consult a doctor.