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Illustration of red blood cells What is hemophilia?

Hemophilia is a rare genetic bleeding disorder. It runs in families and is almost always seen in males. Hemophilia occurs when blood clotting factors don't work as they should. Blood clotting factors help stop bleeding after a cut or injury.

There are two main types of hemophilia:

  • Hemophilia A is caused by a lack of active clotting factor VIII (8). About 1 out of every 5,000 male babies is born with hemophilia A.
  • Hemophilia B (Christmas disease) is caused by a lack of active clotting factor IX (9). It is less common and affects 1 out of 30,000 male babies.

How severe the disease is depends on how much clotting factor is produced and when bleeding most often occurs. There are three levels of hemophilia:

  • Mild hemophilia: Clotting factor level is at least 5% of normal. This type might not be noticed unless there is a lot of bleeding after a major injury or surgery.
  • Moderate hemophilia: Clotting factor level is 1% to 5% of normal. Bleeding normally follows a fall, sprain, or strain.
  • Severe hemophilia: Clotting factor level is less than 1% of normal. Bleeding often happens one or more times a week for no reason.

In rare cases, a person may get acquired hemophilia, a type that does not run in the family. If you have acquired hemophilia, your clotting factors don't work right because your body makes antibodies that attack them.

What causes hemophilia?

Hemophilia A and B are caused by a flaw in a pair of chromosomes. This flaw affects how much clotting factor a person has and how well it works.

What are the symptoms?

Most of the time, hemophilia symptoms are noticed during infancy or childhood. But some people with milder types of the disease may not have symptoms until later in life.

Symptoms noticed in infants include:

  • Bleeding into the muscle, which causes a deep bruise after the baby gets a routine vitamin K shot.
  • Bleeding that goes on for a long time after a baby is circumcised.
  • Bleeding that goes on for a long time after the umbilical cord is cut. This is rare.

Other symptoms include:

  • Bleeding into a joint or muscle, which causes pain and swelling.
  • Bleeding that is not normal after an injury or surgery.
  • Easy bruising.
  • Frequent nosebleeds.
  • Blood in the urine.
  • Bleeding after dental work.

How is hemophilia diagnosed?

Your doctor will do a blood test to find if you have hemophilia. Genetic tests can tell if you are a carrier of the disease. (Only females can be carriers.)

How is it treated?

Most people with this disease can live a normal life with treatment. Hemophilia can be managed with clotting factor replacement therapy. Clotting factors may be injected:

  • On a regular schedule, to prevent bleeds.
  • As needed. You can give yourself a shot of clotting factor just before you do activities with a high risk for injury or when you think that bleeding has already started.

Many people who have hemophilia know when they are bleeding even before there are many symptoms. Work with your doctor to make a plan for what to do if you or your child has a bleed.

Frequently Asked Questions

Learning about hemophilia:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Living with hemophilia:

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  Hemophilia: Should I have regularly scheduled or on-demand clotting factor replacement?


Hemophilia A and B are caused by an inherited defect in a pair of chromosomes. Hemophilia is a sex-linked genetic disease. It is also called an X-linked disease because the defect is on the X chromosome. Fathers pass the defective gene on to their daughters, but not to their sons, and mothers may be carriers. See a picture of the hemophilia inheritance pattern.

Hemophilia almost always occurs in boys. Males get the disease by inheriting the defective gene from their mother. It is very rare for girls to have hemophilia because they must inherit a defective gene from each parent.

The genetic defect affects how much clotting factor a person will produce and how the factor will function. The less normal clotting factor you have, the more severe the hemophilia.

Although hemophilia is a genetic disorder, about one-third of all people with hemophilia have no family history of the condition. In these cases, hemophilia occurs spontaneously when a normal chromosome develops an abnormality (mutation) that affects the gene that determines the production of clotting factor. A child who inherits this mutation may be born with hemophilia or may be a carrier. Only females can be carriers.


Symptoms of hemophilia are usually first noticed during infancy or childhood. But some people who have milder forms of hemophilia may not have symptoms until later in life. Although there are different types of hemophilia, the symptoms are the same.

The following are signs of hemophilia that may be noticed shortly after birth:

  • Bleeding into the muscle, resulting in a deep bruise after receiving a routine vitamin K shot
  • Prolonged bleeding after a male child is circumcised
  • In rare cases, prolonged bleeding after the umbilical cord is cut at birth

Other symptoms of hemophilia include:

  • Bleeding into a joint or muscle that causes pain and swelling.
  • Abnormal bleeding after an injury or surgery.
  • Easy bruising.
  • Frequent nosebleeds.
  • Blood in the urine (hematuria).
  • Bleeding after dental work.

Symptoms of bleeding into a joint (hemarthrosis) include:

  • Warmth and/or tingling in the joint during the early stages of hemarthrosis. This is called an aura. If bleeding is not treated, mild discomfort can progress to severe pain.
  • Swelling and inflammation in the joint, caused by repeated episodes of bleeding. If episodes continue, it may lead to chronic pain and destruction of the joint.
  • An infant's or child's reluctance to move an arm or leg because of bleeding into an affected joint, often first noticed when a child begins to walk.

There are many possible symptoms of bleeding into muscle, including:

  • Bruising.
  • Swelling.
  • Muscle hardening.
  • Tenderness.
  • Pain, especially when large muscle groups are affected.

Occasionally, bleeding into certain muscles (forearm, groin, or leg) puts enough pressure on arteries and nerves to cause a complication called compartment syndrome. A compartment syndrome is a medical emergency that requires immediate treatment to prevent permanent damage to muscle, bones, and other tissue. Symptoms of compartment syndrome include:

  • Weakness and paleness in the affected extremity.
  • Swelling and numbness.
  • Severe pain during movement.
  • Inability to move an extremity (paralysis).

What Happens

In hemophilia, blood does not clot properly. After bleeding starts, it takes longer for bleeding to stop than in a person who has blood that clots normally. A bleeding episode often begins with an injury. Minor injuries may not always cause excessive bleeding. More severe injuries, or injuries in the mouth, more often cause excessive bleeding and frequently require emergency care.

Bleeding into a joint (hemarthrosis), often without an injury, is the most common bleeding problem in people who have severe hemophilia. Bleeding usually occurs in one joint at a time. Bleeding may develop in any joint, but knees, elbows, and ankles are most commonly affected. Sometimes one particular joint, called a target joint, will tend to bleed most often.

Another common symptom of hemophilia is bleeding into a muscle (hematoma), which can be mild or severe. Serious bleeding deep in the muscle can cause significant pain and scarring.

Bleeding in the brain can cause serious brain damage and possibly death. For these reasons, a person with hemophilia who has an injury to the head usually needs urgent treatment with clotting factors.

Even with treatment, bleeding is sometimes difficult to control. Frequent bleeding episodes or a serious injury can lead to complications and excessive blood loss.

With the use of new clotting factor concentrates to treat hemophilia, people who have hemophilia now often have a normal life expectancy.

What Increases Your Risk

Hemophilia is an inherited genetic disease. The risk of a child inheriting hemophilia depends on the parents' genetic makeup.

Sometimes a child is born with hemophilia because part of a normal chromosome changes (mutates) in the eggs or sperm of one or both parents. Medical researchers do not yet know why this mutation occurs in some people.

When To Call a Doctor

Call your health professional if you or your child has one or more of the following symptoms of a bleeding episode:

  • Easy bruising
  • A wound that does not stop bleeding easily or continues to ooze blood
  • Limited motion or obvious swelling in a limb

If you know that your child has hemophilia:

  • Immediate treatment is needed for head injuries, because they are very dangerous. Call 911 or take your child to the nearest hospital emergency room when a head injury occurs. If you are trained in treating hemophilia and have the supplies, begin infusions first.
  • Call your health professional about other types of injuries if you are unsure whether treatment is necessary.

Watchful Waiting

Most people who have hemophilia become skilled at recognizing early signs of bleeding. Work with your health professional to develop a plan for what to do if you or your child has a bleeding episode. This will allow you to start treatment immediately when a bleeding episode is suspected.

A child with hemophilia who is injured should be treated to prevent long-term damage to muscles and joints.

Most people who have hemophilia are cared for by teams who educate the person and his or her family, as well as their health providers, teachers, and co-workers, about hemophilia. If you have hemophilia, inform your health professionals and people you see often, such as co-workers and close friends. Likewise, people who care for your child, such as school officials or daycare staff, should be aware that your child has hemophilia.

People with hemophilia and their families often know a lot about the disease and its treatment. This knowledge can help the person with hemophilia get the right treatment quickly.

Who To See

Your family doctor or general practitioner can diagnose hemophilia. After you or your child is diagnosed with hemophilia, you should be referred to a hemophilia treatment centre. You or your child may receive care from the following health professionals:

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Examinations and Tests

Severe hemophilia is usually diagnosed in early childhood or infancy. But mild forms may not be noticed until adulthood. If a bleeding problem is suspected, the following tests from a single blood sample will help your health professional diagnose hemophilia, its type, and its severity:

  • Prothrombin time (PT) measures certain clotting factors other than those related to hemophilia. Most people with hemophilia have normal results from this test. PT results may be abnormal if another condition is causing bleeding problems.
  • Activated partial thromboplastin time (aPTT) measures clotting factors VIII or IX that are absent or not working properly in people with hemophilia. If aPTT is elevated, you may have hemophilia. But this test cannot determine which type of hemophilia (A or B) is present or even if the defect is in factor VIII or IX. A person with hemophilia usually has abnormal aPTT test results.
  • Factor assay tests determine the severity of hemophilia by measuring the activity levels of factors VIII and IX in the blood, which indicate how well the factors work to clot blood.
    • Mild hemophilia: Clotting factor VIII or IX level is 5% of normal or greater. Mild hemophilia might not be recognized until excessive bleeding develops after a major trauma or surgery.
    • Moderate hemophilia: Clotting factor VIII or IX level is 1% to 5% of normal. Bleeding usually follows a fall, sprain, or strain.
    • Severe hemophilia: Clotting factor VIII or IX level is less than 1% of normal. Bleeding often happens one or more times a week for no apparent reason.
  • Mixing tests mix your plasma with normal plasma to see if it reaches a normal level of clotting factor. If the plasma doesn't reach a normal level, it may mean that your blood has developed inhibitors that are interfering with clotting factor VIII or IX. If this occurs, it may mean that you have a very rare condition called acquired hemophilia.

Genetic screening tests

If you know that hemophilia runs in your family and you are planning to have children, you can be tested for the genetic defect that causes hemophilia to determine whether you are a carrier (only females can be carriers). This will allow you to make informed decisions about pregnancy and prenatal care.

During pregnancy, health professionals can use amniocentesis and chorionic villus sampling (CVS) to test the fetus for the genetic defect that causes hemophilia. If the fetus is found to have hemophilia, you may choose whether you want to complete or terminate the pregnancy. If you decide to continue with the pregnancy, your health professional and a genetic counsellor can help you learn about health issues that affect the fetus before delivery and will affect your child after he or she is born. With modern therapies and by being as careful as possible to prevent bleeding, people with hemophilia can expect to live a normal lifespan.

A child can be tested for hemophilia A after birth with a sample of blood that is taken from the umbilical cord. Testing for hemophilia B in newborns is not effective because newborns naturally have lower levels of clotting factor IX. Blood tests for clotting factor IX deficiency are more effective after a child is 6 months old.

What to think about

There are many types of bleeding disorders that result from a deficiency in one or more clotting factors, although most are very rare. Von Willebrand's disease is the most common of the inherited blood disorders. Like hemophilia, von Willebrand's disease affects clotting factor VIII. But it does so in a different way than hemophilia, and it affects both males and females.

Testing may not be available in all areas of Canada, especially in rural areas. You may need to travel to a regional centre for testing.

Treatment Overview

Treatment of hemophilia is determined by how severe the disease is. Because hemophilia is a genetic disease, treatment often begins at birth. Hemophilia is primarily treated by replacing the absent or abnormal clotting factors to prevent severe blood loss and complications from bleeding.

Viruses can be transmitted through donated blood products, although this happens very rarely. Since 1985, blood products, including clotting factor concentrates, have been screened for viral diseases, such as the human immunodeficiency virus (HIV), hepatitis B, and hepatitis C. Blood that is suspected of being contaminated with these viruses is not used. Current blood-purifying procedures destroy most viruses that are not detected during screening. Some virus risk still exists because of hepatitis A and parvovirus (the virus that causes fifth disease), which are difficult to detect and destroy because of their molecular structure. As a result, in very rare cases some viruses are transmitted through the clotting factor plasma products from donated blood, which can result in complications. Plasma concentrates produced in a lab (using recombinant DNA technology) have almost no risk of transmitting viruses.

Initial treatment

If you are pregnant and know that hemophilia runs in your family, talk to your health professional about hemophilia care. A diagnosis can be made at the time of birth. Sometimes mothers do not know that they are carriers for hemophilia, and in that case you may not discover that your son has hemophilia until he has noticeable bruising or bleeding following an injury. Tests will determine which form of hemophilia is present and how severe it is.

Children and adults with mild hemophilia may not need clotting factor replacement, except before medical or dental procedures or following an injury. For more severe hemophilia, clotting factor replacement can be given intravenously. A child as young as 10 can learn to self-administer the replacement.

Hemophilia treatment centres are available at most large medical centres and are an excellent resource to help you and your family get the best care for this condition. These centres have hematologists, nurses, social workers, physiotherapists, and dentists who specialize in treating people with hemophilia.

Ongoing treatment

Clotting factors are replaced by injecting (infusing) clotting factor replacement into the veins. The severity of hemophilia determines how clotting factors are replaced.

  • Severe forms of hemophilia: Clotting factors may be replaced on a regularly scheduled basis (prophylaxis) to prevent bleeding, or on demand in response to symptoms of a bleeding episode or before an activity that may cause bleeding.
  • Less severe forms of hemophilia: Clotting factors are replaced on demand, when:
    • Bleeding starts, such as after an injury.
    • Bleeding is expected, such as before surgery.
    • When participating in activities that increase the risk for bleeding, such as contact sports.
Click here to view a Decision Point. Hemophilia: Should I have regularly scheduled or on-demand clotting factor replacement therapy?

What To Think About

Medications can be used to help increase clotting factors when undergoing certain medical or dental procedures. These are effective if you have mild hemophilia. And they are used in combination with clotting factors if you have a more severe form of the disease.

Most complications are successfully managed by the injection of clotting factors. But complications can result from treatment with clotting factor replacement.

Chronic pain from joint damage commonly occurs in people who have hemophilia and have one or more severe bleeding episodes inside a joint every year. Narcotics are the most effective medicines to relieve acute joint pain associated with hemophilia. In some cases, joint replacement surgery may be recommended.


Because it is an inherited genetic disease, hemophilia cannot be prevented. If you or any of your immediate family members (parents or siblings) have hemophilia or are carriers and you are thinking about having a child, you may want to talk to a health professional who specializes in the study of inherited disorders (medical geneticist) before becoming pregnant. A genetic counsellor can tell you how likely it is that your child will have hemophilia and how severe it might be.

If you have hemophilia, maintain a healthy body weight to limit the stress on your joints, which can lead to bleeding episodes. Also, talk to your doctor about creating an exercise plan that is safe for people with hemophilia. Regular exercise strengthens the joints and muscles, which helps prevent bleeding.

It is especially important to prevent bleeding into the joints, because it can result in severe disability.

Home Treatment

Home treatment for hemophilia includes learning how to recognize when bleeding has started, administering clotting factors, eating well, and exercising regularly. Learning how to care for yourself or a child with hemophilia at home can lead to a better quality of life.

There are steps you can take to improve your health and prevent bleeding episodes. It is especially important to prevent bleeding into the joints, because it can result in severe disability.

  • Stay at a healthy body weight. If you are overweight, the additional stress on joints can trigger bleeding episodes. For more information, see the topic Weight Management.
  • Exercise with care. Exercises that do not put excess pressure on your joints, such as swimming, usually are recommended.
  • Do not take non-prescription medicines unless your doctor tells you to. Avoid taking non-steroidal anti-inflammatory drugs (NSAIDs), such as ASA, ibuprofen, and Aleve, which can affect the clotting action of your blood.
  • Prevent injuries and accidents around your home.
  • Recognize bleeding episodes so that if an injury or spontaneous bleeding occurs, you can start treatment immediately.

You may be able to treat hemophilia at home by infusing blood-clotting factors. Discuss this option with your health professional.


Medicines can be used in specific situations or in combination with clotting factor replacement to treat hemophilia.

  • Antifibrinolytic agents prevent chemicals in the blood from breaking down blood clots. This type of medicine is used before dental procedures and to treat nosebleeds, because it slows bleeding in the mucous membranes. These medicines are usually used in combination with clotting factors.
  • Thrombin powder helps stop oozing of minor skin wounds in people with hemophilia A.
  • Desmopressin acetate is used, although rarely, to treat mild hemophilia A. This medicine releases unused clotting factor VIII from the cells that line blood vessels, which greatly increases the percentage of clotting factor VIII that is in the blood. Usually, desmopressin acetate is used in addition to clotting factor replacement. But for mild forms of hemophilia, it can be used instead of clotting factor replacement.

Medication Choices

Desmopressin acetate
Antifibrinolytic agents
Thrombin powder

What To Think About

Desmopressin, antifibrinolytic agents, and fibrin glue do not replace clotting factors as the major treatment for hemophilia.


There is no surgical treatment for hemophilia. But the complications of hemophilia, such as joint problems, bleeding around the brain, or swelling that causes pressure buildup in an arm or a leg (compartment syndrome), may require surgery.

Blood-clotting factor replacement is needed before, during, and after any surgical procedure, including some dental procedures.

A person who has mild hemophilia may be given an antifibrinolytic agent or desmopressin acetate before dental procedures. Clotting factors, antifibrinolytic agents, fibrin glue, and possibly desmopressin acetate are usually used in combination to control bleeding in the mouth.

Other Treatment

Bleeding problems caused by hemophilia can be prevented and treated with clotting factor replacement therapy. Clotting factors come from blood donors (plasma-derived clotting factors) or are produced in a laboratory (recombinant or DNA-engineered). The amount of clotting factor needed is determined by how severe the hemophilia is and/or the location of the bleeding. More clotting factor is needed for surgery or bleeding in the brain than for less serious situations, such as routine dental procedures.

Depending upon how severe your disease is, you may choose either to:

  • Receive regularly scheduled infusions of clotting factor to prevent bleeding.
  • Receive clotting factor on demand, that is, only after bleeding starts or before you participate in an activity that will likely cause bleeding.
Click here to view a Decision Point. Hemophilia: Should I have regularly scheduled or on-demand clotting factor replacement therapy?

Sometimes a person's body develops antibodies—called inhibitors—to the injected clotting factor. People who have severe hemophilia or who receive clotting factor replacement for the first time are more likely to develop inhibitors, as are children. When this occurs, specially engineered replacement clotting factors may be required. Other treatment for clotting factor inhibitors includes therapy to suppress the immune system (immunosuppressive therapy).

Other Treatment Choices

Clotting factor replacement
Treatment for people who have inhibitors

What To Think About

Gene therapy may eventually be able to boost the body's ability to make clotting factor. Researchers have developed genes that can cause a person to make clotting factors (for example, factor VIII). These genes have been transplanted into people with hemophilia in research studies. But the people could only produce a very low level of factor VIII. And the clotting factor lasted for less than a year. But no serious side effects were seen. Gene therapy is still a promising treatment for hemophilia, and research is ongoing.

Other Places To Get Help


Association of Hemophilia Clinic Directors of Canada (AHCDC)
30 Bond Street (70 Bond LL)
Toronto, ON  M5B 1W8
Phone: (416) 864-5042
Fax: (416) 864-5251
Email: vogela@smh.toronto.on.ca
Web Address: www.ahcdc.ca

The AHCDC is dedicated to ensuring excellent care for persons with congenital bleeding disorders in Canada through clinical services, research, and education.

Canadian Blood Services
1800 Alta Vista Drive
Ottawa, ON  K1G 4J5
Phone: 1-888-236-6238
(613) 739-2300
Fax: (613) 731-1411
Email: feedback@bloodservices.ca
Web Address: www.bloodservices.ca

Canadian Blood Services (CBS) is a not-for-profit, charitable organization, governed by the provincial and territorial Ministers of Health, whose sole mission is to manage the blood and blood products supply for Canadians. CBS collects approximately 800,000 units of blood annually; screens donors and tests blood or blood product collected for transmissible diseases; and processes them into the components and products that are administered to thousands of patients each year. CBS also manages the Unrelated Bone Marrow Donor Registry (UBMDR) to match donors for Canadian bone marrow transplant patients and for patients in other countries. CBS operates in all provinces and territories except Québec. In Québec, Héma-Québec (www.hema-quebec.qc.ca) performs this role.

Canadian Hemophilia Society
625 President Kennedy Avenue
Suite 505
Montreal, QC  H3A 1K2
Phone: (514) 848-0503
Fax: (514) 848-9661
Email: chs@hemophilia.ca
Web Address: http://www.hemophilia.ca

The Canadian Hemophilia Society provides information, education, and support services to people with inherited bleeding disorders. It also does research into hemophilia and other bleeding disorders with the goal of finding a cure.

KidsHealth for Parents, Children, and Teens
4600 Touchton Road East, Building 200
Suite 500
Jacksonville, FL  32246
Phone: (904) 232-4100
Fax: (904) 232-4125
Web Address: www.kidshealth.org

This Web site is sponsored by Nemours Foundation. It has a wide range of information about children's health, from allergies and diseases to normal growth and development (birth to adolescence). This Web site offers separate areas for kids, teens, and parents, each providing age-appropriate information that the child or parent can understand. You can sign up to get weekly e-mails about your area of interest.

World Federation of Hemophilia
1425 René Lévesque Boulevard West
Suite 1010
Montréal, QC  H3G 1T7 Canada
Phone: (514) 875-7944
Fax: (514) 875-8916
Email: wfh@wfh.org
Web Address: www.wfh.org

The World Federation of Hemophilia works to introduce, improve, and maintain care for people with hemophilia and related bleeding disorders around the world. The WFH provides various health care development programs and publications. The Web site provides general information on the disease, as well as research updates. Links to other organizations and further research resources are also listed.


Other Works Consulted

  • Arnold DM, et al. (2006). Mortality rates and causes of death among all HIV-positive individuals with hemophilia in Canada over 21 years of follow-up. Blood. 108(2): 460–464.
  • Chitlur M, Kulkarni R (2009). Hemophilia and related bleeding disorders. In RE Rakel, ET Bope, eds., Conn's Current Therapy, pp. 419–425. Philadelphia: Saunders Elsevier.
  • Friedman KD, Rodgers GM (2009). Inherited coagulation disorders. In JP Greer et al., eds., Wintrobe's Clinical Hematology, 12th ed., vol. 2, pp. 1379–1424. Philadelphia: Lippincott Williams and Wilkins.
  • Hillman RS, Ault KA (2002). Hemophilia and other intrinsic pathway defects. In RS Hillman, KA Ault, eds., Hematology in Clinical Practice, 3rd ed., chap. 32, pp. 348–359. New York: McGraw-Hill.
  • Poon MC, et al. (1999). Hemophilia and von Willebrand's Disease: 1. Diagnosis, Comprehensive Care and Assessment. Clinical Practice Guidelines (Edition 2, Update 2). Toronto: Association of Hemophilia Clinic Directors of Canada. Also available online: http://www.ahcdc.ca/Care_Assessment.htm.
  • Poon MC, et al. (1999). Hemophilia and von Willebrand's Disease: 2. Management. Clinical Practice Guidelines (Edition 2, Update 2). Toronto: Association of Hemophilia Clinic Directors of Canada. Also available online: http://www.ahcdc.ca/Management.htm.
  • Roberts HR, et al. (2006). Hemophilia A and hemophilia B. In MA Lichtman et al., eds., Williams Hematology, 7th ed., pp. 1867–1886. New York: McGraw-Hill.
  • Walker IR, Julian JA (1998). Causes of death in Canadians with haemophilia 1980–1995. Association of Hemophilia Clinic Directors of Canada. Haemophilia, 4(5): 714–720.


By Healthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Primary Medical Reviewer Anne C. Poinier, MD - Internal Medicine
Specialist Medical Reviewer Brian Leber, MDCM, FRCPC - Hematology
Last Revised October 9, 2009

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.