What happens if glandular fever is not treated?

Glandular fever, also called infectious mononucleosis, can cause marked fatigue, fever, sore throat and swollen glands. Symptoms may make work, study, exercise and social activities difficult. Even when the throat feels better, tiredness can remain and energy may return gradually.

The illness can enlarge the spleen in some people. A blow to the abdomen or strenuous contact activity during this phase can be dangerous, which is why returning to sport should be discussed with a clinician. Rarely, ongoing symptoms need assessment to look for another explanation, including a prolonged fatigue condition.

Rest when needed, drink enough fluid, and use simple measures recommended by a pharmacist or clinician for fever and throat discomfort. Build activity back slowly rather than pushing through severe fatigue. Avoid contact sport, heavy lifting and activities that could cause an abdominal injury until a clinician says they are suitable.

Arrange medical assessment if the diagnosis is uncertain, symptoms are not improving, or fatigue is interfering with daily life. A clinician can examine your throat and glands, review warning signs and decide whether tests or follow-up are appropriate. Do not share drinks or utensils while unwell, and wash hands regularly.

Seek urgent help for severe difficulty breathing or swallowing, intense abdominal pain, fainting, confusion, or sudden deterioration. Prompt advice is also needed for persistent high fever, dehydration, or symptoms that are worsening rather than settling.

Ask when it is safe to return to exercise, whether your work or study needs adjustment, how to manage fatigue, and which changes should trigger a review.