Modifiers matching sickness:

• dangerous,
• little,
• serious,
• basic,
• related,
• common,
• natural,
• scary,
• physical,
• big,
• fatal,
• nasty,
• external,
• temporary,
• foreign,
• preventable,
• curable,
• acute,
• widespread,

Simple categories matching fatal:

• weapon,
• disease,
• illness,
• disorder,
• abnormality,
• trouble,
• disaster,
• infection,
• accident,
• situation,
• pathology,
• complication,
• condition,
• ailment,
• virus,
• result,
• sickness,
• cancer,
• event,
• symptom,
• consequence,
• injury,
• error,
• malignancy,