Suggested thresholds on confirmation of a rise in platelet count (× 109/l)
| *Aspirin has been shown to be efficacious in primary thrombocythaemia, but the level at which it should be initiated is unknown.22 | |
| <450 | No further action required |
| 450–600 | If symptoms, refer |
| If asymptomatic, investigate | |
| 600–1000 | If no secondary cause, refer |
| Consider aspirin* | |
| >1000 | Refer. Avoid aspirin unless thrombotic complications present |