Health and medicine

• 낫다 - to get well, to recover
• 다치다 - To get injured, to get hurt

Disease and sickness

• 콧물 - snot (literally nose water)
• 감기 <感氣> - A cold
• 감기 걸리다 - To catch a cold
• 기침(하다) - a cough, to cough, to have a cough

Hospital

• 문병(하다) - A visit to a sick person, to pay a visit to a sick person
• 병 - Disease, illness
• 수술(하다) - Surgery, to operate on a patient
• 입원(하다) <入院> - Hospitalization, to be hospitalized
• 퇴원(하다) <退院> - Discharge from the hospital, to be discharged from the hospital
• 성형 수술 <成形手術> - Plastic surgery

Misc

• 심하다 - To be severe, to be serious