| Systemic/chronic illness (e.g., autoimmune disorder, cancer) | Alopecia areata, cicatricial alopecia, telogen effluvium |
| Infection (systemic or local) | Cicatricial alopecia, telogen effluvium, tinea capitis |
| Medication exposure (especially chemotherapy) or serious illness within previous three to four months | Telogen effluvium |
| Psychiatric disorder (e.g., psychosis, anxiety, obsessive compulsive disorder) | Trichotillomania |
| Physical stress (e.g., surgery, pregnancy, malnutrition) or life-threatening psychologic stress | Telogen effluvium |
| Tight braids or “pulled-back” hairstyle | Traction alopecia |
| Signs and symptoms of hormonal abnormalities | |
| Hirsutism, amenorrhea, infertility | Androgenetic alopecia (women) |
| Hypothyroidism, other endocrinopathies | Alopecia areata, telogen effluvium |