What is Hemophilia?
Hemophilia is not a disease. It is a condition that some people are born with. The word hemophilia comes from two Greek words: "haima," meaning blood, and "philia," meaning affection.
This rare genetic disorder prevents the blood from forming an effective clot. Without effective blood clotting, internal injuries and large external cuts or wounds may have prolonged bleeding and cannot heal properly.
Myth: People with hemophilia can bleed to death from minor cuts
False. External wounds or cuts are usually not serious. However, internal bleeding can be serious. Internal bleeding can occur in the joints (especially knees, ankles or elbows) and vital organs.
Types of Hemophilia
Normally, when people injure themselves, their blood clots in a few minutes, beginning the healing process. The blood of a person with hemophilia does not clot normally because one of the ingredients needed for making a blood clot is diminished or missing. Some people lack a clotting protein called Factor VIII (factor eight). This factor may be completely or partially missing. This is known as hemophilia A.
Hemophilia A has two other names:
- Classic hemophilia, because it is the most common of the factor deficiencies.
- Factor VIII deficiency hemophilia, because it is the lack of the Factor VIII protein in the blood that causes the clotting problem.
People with hemophilia B are missing, or have too little, Factor IX (factor nine) clotting protein. This bleeding disorder is very similar to hemophilia A, but is much less common.
The Role of Clotting Factors
There are several blood clotting ingredients. Most are proteins. We make them continuously so that the body is always prepared for action should injury occur. As fresh ingredients are made and delivered to the bloodstream, the older ingredients die and are either recycled or eliminated from the body. Normally, low levels of active ingredients circulate, but when an injury occurs it triggers a rapid increase in the manufacture of these ingredients, and the blood stream delivers them to the site where they are needed. Here the clotting ingredients would limit the damage and start the process of wound healing.
Most of the ingredients are called factors. There are 12 primary factors in all, and one of them is Factor VIII. The failure of the body to produce the normal amount of Factor VIII results in hemophilia A.
By the early 1960s, researchers discovered that many proteins were involved in the coagulation pathway. And by early 1960, scientists had identified and named all 12 coagulation factors, and had described the clotting process in detail. In 1962, an international committee named and assigned a Roman numeral to each of these proteins, to avoid confusion. The factors associated with hemophilia A and B were named Factor VIII and Factor IX, respectively. A scheme for the interaction of these factors, termed a coagulation cascade, was published in the science journal Nature in 1964.
The Clotting Process
Even though the blood of persons with hemophilia does not clot normally, they do not bleed more profusely or more quickly than other people. They do, however, bleed for a longer period of time.
Even in severe hemophilia, clotting does take place; however, it is much slower than normal. Generally, the clot cannot withstand the pressure of escaping blood, so it is in a constant state of disruption and doesn't form effectively; so the wound does not heal properly.
The following diagram demonstrates the normal blood clotting process, and how it differs with a bleeding disorder like hemophilia.
Understanding Hemophilia Severity
It is important to know what type of hemophilia you or your loved one has. You should know whether it's a Factor VIII deficiency, Factor IX deficiency, or a more unusual type. As well, you must find out the condition's severity level. This tells you whether you or your loved one is severely, moderately, or mildly affected. Two people with hemophilia can have very different kinds of symptoms depending on the severity of their condition, which are affected by how much factor is working in the bloodstream.
The severity of hemophilia A is defined by the level of the person's factor VIII activity compared to normal levels. This table summarizes the differences:
| Severity | Factor VIII Activity Level | Bleed Types |
|---|---|---|
| Severe | Less than 1% normal | Spontaneous bleeds, usually in joints and muscles, that can occur 1-2 times / week |
| Moderate | 1% to 5% of normal | Spontaneous bleeds, usually in joints and muscles, that can occur 1-2 times / week |
| Mild | 5% to 50% of normal | Bleeds usually only caused by injury or surgery |