| Transient risk factors |
| Infection |
| Central nervous system |
| Ear, sinus, mouth, face, and neck |
| Systemic infectious disease |
| Pregnancy and puerperium |
| Dehydration |
| Mechanical precipitants |
| Head injury |
| Lumbar puncture |
| Neurosurgical procedures |
| Jugular catheter occlusion |
| Drugs |
| Oral contraceptives |
| Hormone replacement therapy |
| Androgens |
| Asparaginase |
| Tamoxifen |
| Glucocorticoids |
| Permanent risk factors |
| Inflammatory diseases |
| Systemic lupus erythematosus |
| Behçet disease |
| Granulomatosis with polyangiitis |
| Thromboangiitis obliterans |
| Inflammatory bowel disease |
| Sarcoidosis |
| Malignancy |
| Central nervous system |
| Solid tumour outside central nervous system |
| Hematologic |
| Hematologic condition |
| Prothrombotic states, genetic or acquired |
| Protein C deficiency |
| Protein S deficiency |
| Antithrombin deficiency |
| Factor V Leiden mutation |
| G20210A prothrombin gene mutation |
| Antiphospholipid syndrome |
| Myeloproliferative neoplasms |
| Nephrotic syndrome |
| Paroxysmal nocturnal hemoglobinuria |
| Hyperhomocysteinemia |
| Polycythemia, thrombocythemia |
| Severe anemia, including paroxysmal nocturnal hemoglobinuria |
| Central nervous system disorders |
| Dural fistulae |
| Other disorders |
| Congenital heart disease |
| Thyroid disease |
