As with most skin conditions, genetics play a role and some people are more prone to dry, cracked lips than others.
Lip skin is thinner than a lot of other skin and doesn’t have any sweat or sebaceous glands. These glands play a key role in producing protective oils that maintain moisture levels and, without them, lips are prone to drying out.
The weather is a significant trigger. People tend to suffer from dry, cracked lips during dry, hot weather or cold windy weather, and so those who spend a lot of time outside due to their jobs or leisure activities are likely to suffer more than others.
Some medications (including medical acne treatments) can cause lips to dry out and crack. And, if you lick you lips regularly, this can also lead to dryness.
You can read more about the causes of dry, cracked lips and how to take care of them in our article.