Diphtheria

What is diphtheria?

An infection caused by a bacterium that makes a poison. It mainly affects the nose and throat, and the poison can harm the heart and nerves.

Signs

Sore throat, fever, swollen neck and weakness. Within a few days a thick grey coating can grow in the throat or nose, making it hard to breathe and swallow.

How it spreads

From person to person, mostly through coughs and sneezes. Crowded living and poor hygiene raise the risk. Some people carry it without feeling ill.

How to protect yourself

Vaccination is the best protection: a set of doses for babies, then booster shots in childhood and the teenage years. It is often given together with tetanus and whooping cough vaccines.

Get medical help

Get medical help immediately for a bad sore throat with a grey coating or trouble breathing or swallowing. Early treatment greatly lowers the chance of serious harm or death.

In Dooram's words, from the World Health Organization. Source: WHO fact sheet: Diphtheria, read 8 October 2026. General information, not medical advice.