About Hemophilia A
Hemophilia A is an X-linked recessive inherited bleeding disorder resulting from deficiency or dysfunction of clotting factor VIII. Pathophysiology involves reduced or abnormal factor VIII protein function, which is critical for the intrinsic tenase complex in the coagulation cascade.
The condition manifests with easy bruising, spontaneous bleeding into joints (hemarthrosis) and muscles (intramuscular hematomas), and spontaneous bleeding in severe forms. Clinical severity correlates directly with factor VIII levels: severe disease (<1% activity) causes spontaneous bleeding and hemarthrosis without provocation; moderate disease (1-5% activity) causes bleeding with minor trauma and significant joint problems; mild disease (5-40% activity) causes bleeding only with significant trauma or surgery. Hemarthrosis leads to progressive arthropathy (arthritis, joint destruction) if untreated, with knees, elbows, and ankles most commonly affected. Intracranial hemorrhage and other serious bleeds represent major causes of morbidity and mortality.
Diagnosis is confirmed by factor VIII activity assay showing reduced levels. Most hemophilia A cases requiring regular treatment tend to be severe or moderate; mild cases may remain undiagnosed until a surgical or traumatic challenge reveals the bleeding tendency.
Common Symptoms of Hemophilia A
Recognizing the signs of Hemophilia A early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Easy bruising and bleeding
- Hemarthrosis (joint bleeds) causing pain and swelling
- Muscle hematomas
- Spontaneous bleeding in severe forms
- Bleeding after trauma or surgery
- Oral and GI bleeding
Who Hemophilia A Affects
Affects males predominantly due to X-linked inheritance; approximately 1 in 4,000-5,000 males worldwide carry the condition. Very rare in females, occurring only with homozygosity, compound heterozygosity, or skewed X-inactivation (lyonization).
Males with the variant can have mild, moderate or severe disease depending on how much factor VIII activity is left; carrier females occasionally have mild to moderate bleeding from unfavorable lyonization. All ethnicities and racial groups affected with similar prevalence. No geographic variation in incidence. Approximately 30% of cases represent de novo mutations. Family history essential for identification of carriers.
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FDA-Approved Treatments for Hemophilia A
There are currently 16 FDA-approved medications for Hemophilia A. These therapies represent the current standard of care and may be used alongside or compared against investigational treatments in active clinical trials. Compare all 16 side by side, with dosing, trial results and warnings from the labels.
Source: openFDA drug labeling data. This list may not include all treatments. Always consult your doctor.
Hemophilia A Medicines in Clinical Trials
Investigational medicines Trial Friend tracks for Hemophilia A, with trial results, safety findings and where each one stands.
Help Paying for Hemophilia A Treatment
Charity funds and drugmaker programs for Hemophilia A, checked at the source.
- From a charity · Hemophilia Federation of AmericaHelping Hands Program fundOpen
Pays for: Emergency living expenses ($250 prepaid card, once per year; referral through HTC or member organization; does not cover medical bills, copays or premiums), up to $250 per year.
The foundation says: “The Helping Hands program is now open on a limited basis for 2026. Due to funding constraints, a maximum of 20 requests will be approved…” - From a charity · TotalAssist (formerly PAN Foundation)Hemophilia fundOpen
Pays for: Out-of-pocket costs for approved medications, up to $12,500 per year. Requires health insurance (any kind).
- From a charity · The Assistance FundHemophilia fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
The foundation says: “WAITLIST — Accepting Waitlist Patients. TAF is currently accepting requests to join the enrollment waitlist for this program. Waitlists a…”
- Alhemo (Concizumab) · NovoCare (Rare Bleeding Disorders)
- Hympavzi (Marstacimab) · Pfizer Hemophilia Connect
- Hemlibra (Emicizumab) · Genentech financial assistance for HEMLIBRA (Co-pay Assistance Program and Genentech Patient Foundation)
- Qfitlia (Fitusiran) · Sanofi HemAssist
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
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Genetic Testing
Genetic testing can confirm a diagnosis, guide treatment decisions, and identify family members who may be at risk.
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Trusted Hemophilia A Resources
Reputable organizations and medical references for learning more about Hemophilia A, including disease registries, foundation resources, and clinical guidelines.