BLEEDING DISORDERS

BLEEDING DISORDERS

Bleeding disorders are the conditions characterized by prolonged bleeding time or clotting time.

Bleeding disorders are of three types:

1. Hemophilia.

2. Purpura.

3. von Willebrand disease.

1. Hemophilia

Hemophilia is a group of sex-linked inherited blood disorders, characterized by prolonged clotting time. However, the bleeding time is normal. Usually, it affects the males, with the females being the carriers.Because of prolonged clotting time, even a mild trauma causes excess bleeding which can lead to death. Damage of skin while falling or extraction of a tooth may cause excess bleeding for few weeks. Easy bruising and hemorrhage in muscles and joints are also common in this disease.

Causes of hemophilia

Hemophilia occurs due to lack of formation of prothrombin activator. That is why the coagulation time is prolonged. The formation of prothrombin activator is affected due to the deficiency of factor VIII, IX or XI.

Types of hemophilia

Depending upon the deficiency of the factor involved, hemophilia is classified into three types:

i. Hemophilia A or classic hemophilia: Due to the deficiency of factor VIII. 85% of people with

hemophilia are affected by hemophilia A.

ii. Hemophilia B or Christmas disease: Due to the deficiency of factor IX. 15% of people with

hemophilia are affected by hemophilia B.

iii. Hemophilia C or factor XI deficiency: Due to the deficiency of factor XI. It is a very rare bleeding

disorder.

Symptoms of hemophilia

i. Spontaneous bleeding.

ii. Prolonged bleeding due to cuts, tooth extraction and surgery.

iii. Hemorrhage in gastrointestinal and urinary tracts.

iv. Bleeding in joints followed by swelling and pain

v. Appearance of blood in urine.

Treatment for hemophilia

Effective therapy for classical hemophilia involves

replacement of missing clotting factor.

2. Purpura

Purpura is a disorder characterized by prolonged bleeding time. However, the clotting time is normal. Characteristic

feature of this disease is spontaneous bleeding under the skin from ruptured capillaries. It causes small tiny hemorrhagic spots in many areas of the body. The hemorrhagic spots under the skin are called purpuric spots (purple colored patch like appearance). That is why this disease is called purpura. Blood also sometimes collects in large areas beneath the skin which are called ecchymoses. necrosis.

4. Necrosis and infarction

Necrosis is a general term that refers to tissue death caused by loss of blood supply, injury, infection,

inflammation, physical agents or chemical substances. Infarction means the tissue death due to loss of

blood supply. Loss of blood supply is usually caused by occlusion of an artery by thrombus or embolus and sometimes by atherosclerosis. Area of tissue that undergoes infarction is called infarct. Infarction commonly occurs in heart, brain, lungs, kidneys and spleen.

3. von Willebrand Disease

von Willebrand disease is a bleeding disorder, characterized by excess bleeding even with a mild injury.

It is due to deficiency of von Willebrand factor, which is a protein secreted by endothelium of damaged blood vessels and platelets. This protein is responsible for adherence of platelets to endothelium of blood vessels during hemostasis after an injury. It is also responsible for the survival and maintenance of factor VIII in plasma. Deficiency of von Willebrand factor suppresses platelet adhesion. It also causes deficiency of factor VIII. This results in excess bleeding, which resembles the bleeding that occurs during platelet dysfunction or hemophilia.