What causes the common cold?

Many different viruses can produce cold symptoms, so having one cold does not create lasting protection against every other cold virus. Infection usually affects the nose and throat, causing a runny or blocked nose, sneezing, sore throat, and cough. Close contact, shared objects, and touching the eyes, nose, or mouth after contact can help the virus move between people.

A cold may irritate nearby areas and sometimes be followed by problems such as sinusitis, an ear infection, or acute bronchitis. Those conditions are separate diagnoses, not proof that the original cold was caused by bacteria.

Rest when you feel unwell, drink fluids regularly, and choose simple foods if your throat or appetite is affected. Warm drinks, saline nasal spray, and humidified air may ease irritation. Wash hands often, cover coughs and sneezes, and avoid sharing cups or towels while symptoms are active.

Use over-the-counter medicines only as directed on the label and check with a pharmacist if you take other medicines, are pregnant, or are treating a child. Antibiotics do not treat viruses.

Arrange medical advice if breathing becomes difficult, chest pain develops, you cannot keep fluids down, or symptoms are severe or worsening. Seek advice for a child who is unusually sleepy, struggling to breathe, or drinking very little. A clinician can assess whether a complication such as sinusitis, croup, or an ear infection needs attention.

Could another infection explain these symptoms? Which treatments are suitable with my current medicines? What changes would mean I should return for review?