Mouth
Sore, cracked lips and mouth corners
Dry, sore, cracked or split lips, often with painful cracks at the corners of the mouth — usually from weather, dehydration, lip-licking or skin sensitivity, but sometimes a clue to iron or vitamin deficiency or a mouth infection, and rarely a sign that needs urgent or cancer checking.
Education and reference only. This explains the common causes of sore, cracked lips and mouth corners and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is sore, cracked lips and mouth corners?
Lips have very thin, delicate skin with little natural oil, so they dry out and crack easily. Most sore, cracked lips come from simple external causes — cold, dry or windy weather, sun, dehydration, and the habit of licking or biting the lips, which removes their protective film and makes dryness worse.
- Get urgent help: Call 999 for swelling of the lips, tongue or throat with breathing difficulty or a tight throat — this can be anaphylaxis, a severe allergic reaction. See your doctor promptly about a lip sore, ulcer or lump that has not healed within three weeks — this needs checking for mouth or lip cancer.
- Self-care: Most cracked, sore lips improve quickly with simple protection and moisture.
About sore, cracked lips and mouth corners
Lips have very thin, delicate skin with little natural oil, so they dry out and crack easily. Most sore, cracked lips come from simple external causes — cold, dry or windy weather, sun, dehydration, and the habit of licking or biting the lips, which removes their protective film and makes dryness worse. Cracks and soreness at the corners of the mouth are common too, sometimes from saliva pooling there, from a yeast or bacterial infection, or from dry, sensitive skin. Occasionally, persistent or recurrent cracking points to something internal: iron or vitamin deficiencies can leave the lips and mouth corners sore and split. Most cracked lips heal quickly with protection and moisture. Two situations need a different response: lip or tongue swelling with breathing difficulty, which can be a severe allergic reaction, and a lip sore or ulcer that does not heal within three weeks, which should be checked for mouth or lip cancer.
When to get help
Call 999 or go to A&E if sore, cracked lips and mouth corners comes with any of these warning signs:
- Call 999 for swelling of the lips, tongue or throat with breathing difficulty or a tight throat — this can be anaphylaxis, a severe allergic reaction.
- See your doctor promptly about a lip sore, ulcer or lump that has not healed within three weeks — this needs checking for mouth or lip cancer.
- Seek urgent help if the lips or face swell rapidly after a food, sting or medicine, with hives or feeling faint.
- See your doctor if cracked corners of the mouth keep returning with a sore tongue, tiredness and pallor, as iron deficiency may be the cause.
- Seek advice if lips or mouth corners become hot, red, swollen, weeping or crusted, suggesting infection.
When to see a doctor
Cracked, sore lips usually heal within a week or two with regular moisturising, hydration and stopping lip-licking, so they rarely need a doctor. Book a routine appointment if cracks at the corners of the mouth keep returning, look infected, or come with a sore tongue, tiredness and pallor, as an infection or an iron or vitamin deficiency may need treating. See your doctor promptly — and specifically — about any lip sore, ulcer or lump that has not healed within three weeks, as a non-healing lip sore needs checking for cancer. Treat lip, tongue or throat swelling with breathing difficulty as a 999 emergency.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of sore, cracked lips and mouth corners
Sore, cracked lips and mouth corners has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
Most cracked, sore lips improve quickly with simple protection and moisture. Apply a plain, unperfumed lip balm or emollient regularly, especially before going out in cold, dry or sunny weather, and choose a balm with sun protection outdoors. Drink enough fluids to stay hydrated, as dryness worsens chapping. Try hard to break the habit of licking or biting your lips, which strips away their protective film and makes cracking worse. Keep the corners of the mouth clean and dry, and avoid lip products, toothpastes or foods that seem to irritate. A balanced diet supports healing. If cracks at the corners look infected, keep returning, or come with a sore tongue and tiredness, see a pharmacist or doctor, as an infection or a deficiency may need treating.
Answers
Sore, cracked lips and mouth corners: frequently asked questions
Why do my lips keep cracking?
Lips have thin skin with little natural oil, so cold, dry or windy weather, sun, dehydration and lip-licking dry them out and crack them. Regular lip balm, staying hydrated and not licking your lips usually clears it up.
What causes cracks at the corners of my mouth?
Common causes are saliva pooling in the corners, a yeast or bacterial infection, and dry, sensitive skin. Persistent or recurrent cracking can sometimes point to iron or vitamin deficiency, especially with a sore tongue, tiredness and pallor.
When should a lip problem be checked urgently?
Call 999 if the lips, tongue or throat swell with breathing difficulty, as this can be a severe allergic reaction. Separately, see your doctor promptly about any lip sore or ulcer that has not healed within three weeks, as it needs checking for cancer.
Can vitamin or iron deficiency cause sore lips?
Yes. Iron deficiency in particular can cause sore, cracked corners of the mouth and a sore tongue, often with tiredness and pale skin. If cracking keeps returning with these features, ask your doctor whether a blood test would help.
Sources
Where this is drawn from
- NICE CKS: Angular cheilitis.
- British Association of Dermatologists: lip care.
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