Medical Conditions and Illnesses in the Athlete
Respiratory and allergic disease
Exercise-induced bronchoconstriction is common in endurance athletes and is treated with pre-exercise short-acting beta-agonists plus controller therapy. Distinguish it from poor conditioning and vocal cord dysfunction. Anaphylaxis is treated with intramuscular epinephrine without delay; antihistamines are adjuncts only, and the athlete should not return to play the same day.
Endocrine and hematologic issues
Type 1 diabetes requires individualized carbohydrate and insulin plans, glucose monitoring before, during, and after exercise, and awareness that delayed hypoglycemia can occur hours later. Sickle cell trait is not a contraindication to sport but carries risk of exertional rhabdomyolysis, heat illness, and splenic infarction with extreme exertion, dehydration, or altitude; hydration, pacing, and acclimatization are protective.
Infection and return to play
Infectious mononucleosis warrants avoidance of contact for about four weeks because of splenic enlargement and rupture risk; return requires clinical recovery and, in some guidance, sonographic splenic normalization. Fever, myalgia, and systemic symptoms warrant withdrawal. Skin infections - tinea, impetigo, herpes gladiatorum, and MRSA - require treatment and coverage before contact.
Chronic disease
Hypertension thresholds in children are percentile-based; in adults, measurement technique matters. Athletes with a single kidney, seizure disorders, or bleeding disorders need individualized clearance and sport selection.
Traps
Do not diagnose asthma purely on symptoms; confirm with spirometry or challenge testing. Do not clear an athlete with mono on the basis of feeling better alone. Do not assume sickle cell trait is protective or disqualifying.
Worked example: a college rugby player has fever, sore throat, and posterior cervical nodes, and tests positive for EBV. He is withheld from contact for four weeks and returns when clinically recovered.