What is the most common cause of swimmer's ear?

The most common cause of swimmer's ear is trapped moisture in the ear canal, which allows irritation and infection to develop. The medical term is otitis externa, and it affects the canal between the outer ear and the eardrum.

Water can soften the skin lining the canal. Rubbing with cotton buds, scratching or inserting objects can then create tiny breaks that let germs multiply. Earache, tenderness when the outer ear is moved, itch, discharge or muffled hearing may follow. The condition can occur without swimming when moisture, eczema or irritation affects the canal.

Keep the ear dry and avoid putting fingers, cotton buds or home remedies into the canal. Do not swim until symptoms have settled. A GP consultation can confirm the cause and check the eardrum; prescribed ear drops may be needed, and the correct type depends on the examination.

Arrange prompt assessment for severe pain, spreading redness, fever, facial weakness, marked hearing change, dizziness or discharge. People with diabetes or a weakened immune system should seek advice early because ear-canal infections can become more serious.

Ask whether the eardrum can be seen, which drops are suitable, how to keep the canal dry, and when it is safe to swim again.