Venous stasis – the normally central stream of platelets within laminar flow become more peripheral, near endothelium:
- bed rest
- immobilised limb
- cast
- post-operative
- paralysis
- congestive cardiac failure (CCF)
- pelvic obstruction
Intimal damage:
- trauma to vein wall – intravenous cannula
- varicose veins
- inflammation around veins (especially pelvic)
Hypercoagulability
- trauma – increased stickiness of platelets
- surgery
- childbirth
- injury
- hyperviscosity
- cancer
- oral contraceptive pill – with oestrogens
