Cardiac | Arrhythmia | 2 |
| Atrial septal defect or patent foramen ovale | 4 |
| Coronary artery disease (including myocardial infarction, bypass surgery, and percutaneous intervention) | 8 |
| Hypertension | 39 |
| Hypotension | 2 |
| Pacemaker | 1 |
| Valvular heart disease or surgery | 3 |
Decompression illness | Within limits | 29 |
Outwith limits | 6 |
Endocrine | Hypothyroidism (on thyroxine) | 7 |
| Insulin dependent diabetes mellitus | 6 |
| Non-insulin dependent diabetes | 1 |
Ear, nose, throat | Ear clearing difficulty | 8 |
| Hay fever or nasal polyp | 5 |
| Sinusitis | 1 |
| Perforated ear drum | 4 |
Eyes | Laser iridectomy | 1 |
Gastrointestinal | Colonic carcinoma | 5 |
| Colostomy | 1 |
| Crohn’s disease | 3 |
| Diverticular disease | 1 |
| Hiatus hernia | 2 |
| Irritable bowel syndrome | 1 |
| Oesophageal stricture | 1 |
General | Various | 47 |
| Medication | 43 |
Haematology | Antithrombin III deficiency | 1 |
| Haemophilia | 1 |
| Polycythaemia | 1 |
| von Willebrand’s disease | 1 |
Neurology | Cerebrovascular disease | 2 |
| Epilepsy | 7 |
| Erb’s palsy | 1 |
| Head injury | 1 |
| Migraine | 11 |
| Multiple sclerosis | 1 |
| Subarachnoid haemorrhage | 1 |
Orthopaedic | Spinal surgery or prolapsed intervertebral disc | 13 |
| Joint surgery | 4 |
Psychiatric | Depression or anxiety | 18 |
| Claustrophobia | 3 |
Renal | Pyelonephritis | 1 |
| Proteinuria | 1 |
Respiratory | Asthma | 98 |
| Chronic obstructive pulmonary disease | 2 |
| Cystic fibrosis | 1 |
| Pneumothorax | 8 |
Rheumatology | Rheumatoid arthritis | 2 |
| Systemic lupus erythematosus | 1 |
| Raynaud’s disease | 1 |
Vascular | Hereditary haemorrhagic telangiectasia | 1 |
Combined total | | 413 |