Blood clots form to prevent blood loss both inside and outside the body. But they can become dangerous if they get dislodged from where they form.
Sikhumbuzo Notshe of the Stormers (L) is tackled by Waisake Naholo of the Highlanders (R) during a Super Rugby match between New Zealand’s Highlanders and South Africa’s Stormers.
EPA-EFE/NIC BOTHMA