Blood flow depends on a balance between coagulation inhibitors and activators. The upsetting of this equilibrium will result in haemorrhages or thrombosis.
A large haemorrhage can become life-threatening because of a drop in blood pressure. Controlling the bleeding depends on the part of the body which is injured and on the amount of bleeding. When the usual treatment of external haemorrhages is based on direct or remote compression, the control of an internal haemorrhage usually requires surgery. However, some drugs such as anti-fibrinolytic agents can be used to reduce the size of the haemorrhage.
When the body is immobilised, the blood flow is slowed down which can cause a blood clot in the lower, and even upper limbs. Treatment depends on the progress of the condition: local support of veins, administration of anticoagulants or thrombolytics. If the blood clot breaks away and moves towards the pulmonary artery, the patient is at risk of a pulmonary embolism.