Years after Kennedy's death, it was revealed that in September 1947, while Kennedy was 30 and in his first term in Congress, he was diagnosed by Sir Daniel Davis at The London Clinic with Addison's disease, a rare endocrine disorder.
Beberapa tahun setelah kematian Kennedy, terungkap bahwa pada September 1947, ketika Kennedy berusia 30 tahun dan sedang menjalani masa jabatan pertamanya di Kongres, ia didiagnosis menderita penyakit Addison, gangguan endokrin langka, oleh Sir Daniel Davis dari The London Clinic.