Medical Conditions in Athletes
Core concepts
Athletes present with conditions where exercise interacts with disease: exercise-induced asthma/bronchoconstriction, anaphylaxis risk, type 1 diabetes, hypertension, cardiac conditions, concussion, heat illness, and infectious mononucleosis. Understand exercise-induced bronchoconstriction (EIB): symptoms 5-15 minutes after exercise, worse in cold dry air, diagnosed with exercise challenge or methacholine testing, treated with short-acting beta-agonist pre-exercise and controller inhaled steroids. Know diabetes management: pre-exercise glucose targets, carbohydrate intake, and hypoglycemia recognition. Understand mononucleosis return-to-play: splenic enlargement risk, no contact sports for roughly 4 weeks (or longer with splenomegaly).
Traps
A common trap is confusing EIB with poor conditioning or vocal cord dysfunction (inspiratory stridor, no response to bronchodilators). Another is clearing an athlete with mononucleosis too early-risk of splenic rupture persists while the spleen is enlarged. Do not miss hypertrophic cardiomyopathy as a cause of exertional syncope; syncope during exercise is cardiac until proven otherwise, whereas syncope after exercise is more often benign (vasovagal, dehydration).
Rule of thumb
Exertional syncope or chest pain = stop, evaluate for cardiac cause. Syncope after stopping = usually benign but still evaluate. For diabetes, "check before, fuel during, check after."
Worked example
A cross-country runner has cough and wheeze only during cold-weather races. Spirometry is normal at rest. The pattern suggests EIB; a pre-exercise SABA trial and inhaled corticosteroid controller are appropriate, and vocal cord dysfunction should be considered if there is no bronchodilator response.