Lifelines includes predominantly health-related variables. A large portion of those variables are aimed to assess whether participants have particular diseases and/or (undiagnosed) symptoms, via self-report questionnaires.
Variables that more neutrally assess the (measured and/or self-reported) physical characteristics of participants, independent of specific diseases and symptoms, can be found here.

In Lifelines, variables in this section are organized in the following subsections:

1. Acne
2. Adrenal gland disorders
3. Allergies
4. Blood disorders
5. Bronchial Hyperresponsiveness (BHQ)
6. Cancer
7. Cardiovascular diseases
8. Cardiovascular symptoms
9. Chronic diseases (Covid-19)
10. Connective Tissue Disease (CSQ)
11. Covid-19 infection
12. Diabetes
13. Digestive system diseases
14. Diseases (other)
15. Diseases (PROMAS)
16. Ear conditions
17. Eczema measure (POEM)
18. Eye conditions (general)
19. Eye conditions (OQ)
20. Eating disorders
21. Fatigue (general)
22. Fatigue (CDC)
23. Functional bowel symptoms (Rome III)
24. Fatigue (PROMIS)
25. Fatigue (CIS)
26. Fever
27. General health (PROMIS)
28. Insomnia
29. Kidney & bladder diseases
30. Menopausal Symptoms (GCS)
31. Mental illnesses
32. Musculoskeletal conditions
33. Musculoskeletal symptoms
34. Musculoskeletal pain (WPI)
35. Neurological disorders
36. Occupational eczema (NOSQ)
37. Oral cavity conditions
38. Ostheoarthritis (WOMAC)
39. Reproductive organ diseases
40. Respiratory diseases
41. Respiratory problems (general)
42. Respiratory problems (ELON)
43. Skin conditions
44. STDs
45. Symptoms (Covid-19)
46. Symptoms (SCL-90)
47. Upper extremities (UEFS)