How is measles transmitted?

The virus can remain in an indoor space for a period after an infected person has left. Close contact, shared air, and crowded settings can therefore allow transmission even without touching the person. Someone may spread measles before the rash is obvious, so a person with fever, cough, runny nose, red eyes, or a spreading rash should avoid gatherings and contact with people who are vulnerable.

Measles is highly contagious, but a rash alone does not establish the diagnosis. A clinician considers the pattern of symptoms, exposure history, and vaccination history. Read more about [Measles](/conditions/measles/), [Fever](/symptoms/fever/), and [Swollen Glands](/symptoms/swollen-glands/).

Call a GP or clinic before arriving and explain that measles exposure is possible; this lets the team arrange assessment without exposing people in a waiting room. Stay home, limit visitors, improve ventilation, and do not share close indoor time with infants, pregnant people, or anyone with reduced immunity until you receive advice. Check vaccination records and tell the clinician when exposure occurred and whether symptoms have started. A [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can help plan assessment, while [MMR Vaccination](/treatments/preventive-care-and-vaccination/mmr-vaccination/) helps prevent measles.

Seek prompt medical advice after a known exposure, especially if the exposed person is a young child, pregnant, or immunocompromised. Arrange urgent help for breathing difficulty, unusual drowsiness, confusion, dehydration, a seizure, or a rapidly worsening illness. Phone ahead and mention the suspected infection rather than walking into a clinic unannounced.

Ask whether testing or monitoring is needed, how long to stay away from others, and whether household contacts need advice about vaccination or observation. Also ask which symptoms should trigger same-day review.