Upper Respiratory Tract Illness

The upper respiratory tract is the nose, sinuses, pharynx and larynx, and infection there produces the familiar inflammation of a blocked or runny nose, sneezing, a sore throat and a cough. The great majority are viral, and antibiotics have no role in an uncomplicated cold.

High training and competition loads may coincide with a greater risk of acute respiratory illness, but the relationship is complex. Proposed contributors include altered immune regulation, inadequate recovery, poor sleep, nutritional factors, travel, crowding and greater exposure to respiratory pathogens, and endurance and winter sport, monotonous or rising load, altitude and travel are recognised associations. The traditional open-window idea, of a temporary immune dip after intense exercise, remains debated and should not be treated as a complete explanation.

Cardiac involvement is the reason caution matters most. Myocarditis is an uncommon but potentially serious complication of viral infection, and strenuous exercise should be avoided during fever or systemic illness, because occult cardiac involvement may be present and exercise in the setting of myocarditis may increase the risk of arrhythmia and other complications.

An uncomplicated viral upper respiratory infection causes nasal congestion, a runny nose, sneezing, a mild sore throat, sometimes a dry cough and a little malaise, without fever and with a general sense of being reasonably well. Most symptoms improve within about a week, although cough and nasal symptoms may last longer, so persistence alone does not signal a complication, and reassessment is prompted by worsening, systemic illness or a lack of any improvement over the expected course.

The clinical skill is to distinguish this uncomplicated picture from systemic or cardiopulmonary involvement. Symptom location can give a rough initial clue, and the older neck check, treating above-neck symptoms as lower risk than below-neck ones, has been widely taught, but it has little validation and should not be used on its own to clear an athlete.

A better approach is a structured assessment of severity, of systemic and cardiopulmonary symptoms, and of resting observations. An athlete who is afebrile, has only mild localised symptoms, normal resting observations and no cardiopulmonary features may try a short trial of reduced-intensity exercise, whereas exercise should not begin where there is fever, marked fatigue, aching, a significant cough, chest symptoms, abnormal observations or a sense of being systemically unwell.

Most upper respiratory infections are diagnosed clinically and need no tests. Investigation is reserved for atypical, severe or specific presentations. Where bacterial pharyngitis is suspected, the FeverPAIN or Centor clinical criteria guide management and antibiotic decisions rather than routine throat swabbing, which is not needed in most otherwise healthy patients.

Infectious mononucleosis, or glandular fever, should be considered in an adolescent or young adult with marked fatigue, fever, an exudative sore throat, posterior cervical lymphadenopathy, palatal petechiae or possible hepatosplenomegaly, where a full blood count (FBC) with differential, liver biochemistry and Epstein-Barr virus (EBV) serology are useful, remembering that very early serology may be negative. Testing for coronavirus disease 2019 (COVID-19) follows prevailing advice. Any suggestion of cardiac involvement, such as new chest pain, breathlessness, palpitations or disproportionate fatigue, calls for prompt cardiac assessment.

Treatment of an uncomplicated cold is supportive: rest, fluids, and simple analgesia such as paracetamol for aches and fever, with the illness resolving over about a week. Antibiotics are not indicated for a viral upper respiratory infection, in keeping with antimicrobial stewardship, and are reserved for a genuine bacterial complication. Decongestants offer limited benefit and are used selectively, with attention to contraindications, cardiovascular effects and anti-doping status, and topical nasal preparations kept to short-term use to avoid rebound congestion.

Two points are specific to athletes. The first is anti-doping. Some cold and flu remedies contain restricted substances, most notably pseudoephedrine, a decongestant prohibited in competition above a urinary concentration of 150 micrograms per millilitre, and athletes are generally advised to stop pseudoephedrine-containing medication at least 24 hours before the in-competition period, though elimination varies and this does not guarantee a concentration below the threshold. Every specific product, including combination remedies, should be checked on Global Drug Reference Online, and strict liability means the athlete is responsible for whatever is found in their sample.

The second is the decision about load: reducing or pausing training while unwell, not exercising through fever or systemic illness, and limiting the spread of infection through a squad. Prevention has a place too, including hand hygiene, not sharing bottles, managing load and sleep, good nutrition, and relevant vaccination such as influenza and COVID-19.

Return to sport is graded. For an athlete recovering from an asymptomatic or mild respiratory infection, a practical approach is to begin with around ten to twenty minutes of sport-specific exercise at roughly sixty to seventy per cent of usual intensity, stopping for excessive fatigue, disproportionate breathlessness, chest discomfort, dizziness, palpitations, unusual muscle or joint pain, an unexpectedly high effort for the workload, or a general feeling of being unwell. Symptoms are monitored during, immediately after and over the following day before load is increased. Any athlete who was febrile or systemically unwell should be fully recovered and reliably afebrile first, with a low threshold to stop and seek cardiac assessment if chest pain, breathlessness, palpitations or unusual fatigue appear on resuming.

Two situations need specific care. In confirmed infectious mononucleosis, no exercise should occur while the athlete is febrile or unwell, light non-contact activity may be reintroduced gradually once symptoms have resolved, and contact or collision sport, heavy lifting and marked straining should be avoided for at least the first three to four weeks from symptom onset and until clinically recovered, and for longer where symptoms persist or splenomegaly is suspected, since baseline spleen size varies and imaging is not a reliable sole clearance test. After COVID-19, the same symptom-led framework applies, with cardiac and respiratory assessment reserved for those with cardiopulmonary symptoms rather than routine screening after mild illness.

• •The International Olympic Committee consensus on acute respiratory illness in athletes provides a structured clinical assessment, return-to-sport checklists and a graded exercise-challenge approach, and it treats the historical neck-check rule as having limited supporting evidence and not for use in isolation.
• •United Kingdom guidance on acute sore throat and acute cough supports clinical assessment, self-care and antimicrobial stewardship, reserving antibiotics for genuine bacterial infection.
• •National Health Service guidance on glandular fever covers Epstein-Barr virus testing and avoiding strenuous and contact sport because of the risk of splenic rupture.
• •UK Anti-Doping and World Anti-Doping Agency medication guidance set out which remedies are permitted and the in-competition limit on pseudoephedrine.

• •Acute respiratory illness in athletes is usually a mild, self-limiting viral upper respiratory infection, but symptom site alone does not prove infection.
• •Assess severity, systemic and cardiopulmonary symptoms and resting observations rather than relying on the older neck check.
• •Athletes should not exercise while febrile or systemically unwell, because of the uncommon but serious risk of myocarditis.
• •An uncomplicated cold needs no tests and no antibiotics, and management is supportive.
• •Check cold and flu remedies on Global Drug Reference Online, since pseudoephedrine is restricted in competition above a set urinary level.
• •Return to sport is graded, using a monitored exercise challenge, with specific caution over the spleen in glandular fever and cardiac symptoms after viral illness.