Bleeding that won’t stop after a small cut. Large bruises appearing without any clear injury. Unexpected blood in your urine. These signs can be alarming — and in rare cases, they may point to acquired hemophilia, a serious but uncommon bleeding disorder that develops later in life.
- What Is Acquired Hemophilia?
- Key Features of Acquired Hemophilia
- Acquired Hemophilia vs. Hereditary Hemophilia
- Causes and Triggers of Acquired Hemophilia
- 1. Autoimmune Disorders
- 2. Medications
- 3. Cancer
- 4. Infections
- 5. Pregnancy and Postpartum Period
- Symptoms of Acquired Hemophilia
- Common Warning Signs
- How Symptoms Differ from Hereditary Hemophilia
- Potential Complications
- How Acquired Hemophilia Is Diagnosed
- Step 1: Patient History and Physical Examination
- Step 2: Laboratory Tests
- Step 3: Additional Investigations
- Treatment Options for Acquired Hemophilia
- 1. Controlling Bleeding
- 2. Suppressing the Immune Attack
- 3. Treating the Underlying Cause
- 4. Supportive Care
- Living with and Preventing Future Bleeding Episodes
- Lifestyle Precautions
- Follow-Up and Monitoring
- Conclusion
- Frequently Asked Questions
- 1. Can acquired hemophilia go away on its own?
- 2. How long does treatment for acquired hemophilia usually last?
- 3. Is acquired hemophilia genetic?
- 4. Can acquired hemophilia come back after remission?
- 5. What should I do if I’m diagnosed with acquired hemophilia?
Unlike hereditary hemophilia, which is present from birth due to genetic mutations, acquired hemophilia often strikes without warning in adults who’ve never had bleeding issues before. The underlying cause? An autoimmune response in which the body’s own immune system attacks the proteins (clotting factors) that help blood clot. Without these proteins functioning properly, the body struggles to stop bleeding, even from minor injuries.
While rare — affecting about 1.5 people per million each year — acquired hemophilia can be life-threatening if not recognized and treated promptly. Many healthcare providers may never encounter a case, making early recognition even more critical.
In this guide, we’ll cover:
- What acquired hemophilia is and how it works
- How it differs from hereditary hemophilia
- Common causes and triggers
- Symptoms and bleeding patterns to watch for
- Diagnostic steps and medical tests
- Treatment strategies and long-term management
- Lifestyle precautions for safer living with the condition
What Is Acquired Hemophilia?
Acquired hemophilia is an autoimmune blood clotting disorder. In this condition, the immune system mistakenly produces antibodies that target and neutralize certain clotting proteins — most often factor VIII, a critical player in the clotting process.
When these antibodies (called inhibitors) block factor VIII, the body’s normal clotting cascade is disrupted. As a result, even minor injuries can lead to excessive, prolonged, or spontaneous bleeding.
Key Features of Acquired Hemophilia
- Not genetic — it develops later in life
- Affects both men and women equally
- Often linked to other health conditions such as autoimmune diseases, cancers, or recent childbirth
- More common in older adults — about 80% of cases occur in people over 60
A major challenge with acquired hemophilia is that it can appear suddenly. Someone who’s undergone surgery or dental work in the past without issue may suddenly experience uncontrollable bleeding from a minor procedure.
Unlike hereditary hemophilia — which usually causes joint bleeding (hemarthroses) — acquired hemophilia tends to cause soft tissue bleeding, large bruises, and internal hemorrhages.
Acquired Hemophilia vs. Hereditary Hemophilia
Though they share a name, acquired and hereditary hemophilia are fundamentally different in cause, onset, and presentation.
| Feature | Hereditary Hemophilia | Acquired Hemophilia |
|---|---|---|
| Cause | Genetic mutation leading to low/absent clotting factor from birth | Autoimmune antibodies attack existing clotting factors |
| Onset | Infancy or early childhood | Sudden onset in adulthood |
| Gender Distribution | Mostly males (X-linked inheritance) | Affects both sexes equally |
| Typical Bleeding Sites | Joints, deep muscles | Skin, soft tissues, mucous membranes |
| Family History | Common | Rare |
| Treatment Goal | Replace missing clotting factor | Control bleeding + suppress immune attack |
Example:
A boy born with hereditary hemophilia A will have lifelong bleeding tendencies and frequent joint bleeds. In contrast, a healthy 70-year-old woman could suddenly develop large, unexplained bruises and internal bleeding due to acquired hemophilia — despite having no prior bleeding history.
Causes and Triggers of Acquired Hemophilia
In about half of all cases, no clear cause is found — this is called idiopathic acquired hemophilia. The other half can be linked to certain underlying conditions, medications, or physiological events.
1. Autoimmune Disorders
Conditions that cause the immune system to attack the body’s own tissues can also trigger the production of antibodies against clotting factors. Common examples include:
- Systemic lupus erythematosus (SLE)
- Rheumatoid arthritis
- Multiple sclerosis
- Inflammatory bowel disease (Crohn’s or ulcerative colitis)
- Autoimmune hepatitis
In these cases, the immune system is already primed for overreaction, making clotting factors an accidental target.
2. Medications
Some drugs can spark immune reactions that lead to inhibitor formation. These include:
- Antibiotics (e.g., penicillin)
- Interferon (used for hepatitis C and some cancers)
- Certain cardiac medications
- Antiepileptics (e.g., phenytoin)
The reaction can happen weeks to months after starting the medication and usually improves once the drug is discontinued — though treatment for the inhibitor is still needed.
3. Cancer
Both blood cancers (like lymphoma or leukemia) and solid tumors can alter immune function, increasing the risk of acquired hemophilia. The connection may be due to immune dysregulation from the cancer itself or from treatments like chemotherapy.
4. Infections
Occasionally, viral or bacterial infections can trigger molecular mimicry, where the immune system mistakes clotting factors for parts of the infection and attacks both.
5. Pregnancy and Postpartum Period
Postpartum acquired hemophilia is a recognized condition, often appearing within 3–6 months after delivery. Symptoms may be mistaken for normal postpartum bleeding but can progress rapidly and dangerously.
Symptoms of Acquired Hemophilia
Acquired hemophilia can present suddenly and often in alarming ways. Because many patients have no prior history of bleeding disorders, these symptoms can be easily overlooked or misdiagnosed at first.
Common Warning Signs
- Large, spontaneous bruises — often without any injury; can appear deep purple or blue
- Soft tissue bleeding — bleeding into muscles or under the skin
- Prolonged bleeding from minor cuts or injections
- Mucosal bleeding — from the nose, gums, or inside the mouth
- Blood in urine (hematuria) or stools (melena)
- Post-surgical or postpartum hemorrhage that is more severe than expected
How Symptoms Differ from Hereditary Hemophilia
One key distinction is joint bleeding — a hallmark of hereditary hemophilia but rare in acquired hemophilia. Instead, the bleeding is more diffuse and often internal, which makes it harder to detect early.
Example Case:
A 68-year-old man undergoes a routine hernia surgery and seems fine initially, but two days later, he develops severe swelling and pain in his thigh. Imaging reveals a large hematoma — bleeding within the muscle — despite normal platelet counts. This unusual presentation prompts further testing, leading to a diagnosis of acquired hemophilia.
Potential Complications
If untreated, acquired hemophilia can lead to:
- Severe blood loss and anemia
- Compartment syndrome (dangerous swelling in a muscle compartment)
- Organ damage from internal bleeding
- Life-threatening hemorrhage after injury or surgery
The mortality rate can be as high as 20%, often due to delayed diagnosis — making rapid recognition vital.
How Acquired Hemophilia Is Diagnosed
Diagnosing acquired hemophilia requires a careful combination of clinical suspicion and laboratory confirmation. Because it’s so rare, doctors must rule out other, more common causes of bleeding first.
Step 1: Patient History and Physical Examination
The doctor will look for:
- No personal or family history of bleeding disorders
- Recent triggers such as childbirth, surgery, new medications, or illnesses
- Pattern of bleeding (soft tissue and mucosal rather than joint bleeding)
Step 2: Laboratory Tests
Key blood tests include:
| Test | Expected Result in Acquired Hemophilia | Purpose |
|---|---|---|
| aPTT (activated partial thromboplastin time) | Prolonged | Measures intrinsic clotting pathway function |
| PT (prothrombin time) | Normal | Helps rule out other clotting problems |
| Mixing study | aPTT remains prolonged | Indicates presence of an inhibitor rather than factor deficiency |
| Factor VIII activity assay | Low | Confirms target of the inhibitor |
| Inhibitor titer (Bethesda assay) | Positive | Measures strength of the antibody |
Step 3: Additional Investigations
If an underlying condition is suspected (autoimmune disease, cancer), additional imaging, antibody testing, or biopsies may be ordered.
Tip for Patients: If you experience unusual bleeding and have no prior history of hemophilia, request a full clotting panel including factor VIII activity — this speeds up diagnosis.
Treatment Options for Acquired Hemophilia
Treatment focuses on two main goals:
- Control active bleeding
- Eliminate the inhibitor antibody
Because this is a medical emergency in many cases, treatment often starts before full test results are back.
1. Controlling Bleeding
When factor VIII is neutralized by antibodies, simply giving more factor VIII won’t work. Instead, doctors use bypassing agents that help the clotting process skip the blocked step.
Common options include:
- Recombinant activated factor VII (rFVIIa)
- Activated prothrombin complex concentrate (aPCC)
- Emicizumab (though more common in hereditary hemophilia, it is being studied for acquired cases)
For minor bleeding, close monitoring and local measures (pressure, ice packs) may be enough, but major bleeds require urgent hospital care.
2. Suppressing the Immune Attack
To stop the immune system from producing antibodies, immunosuppressive therapy is used, often for several months.
Common regimens:
- Corticosteroids (prednisone)
- Cyclophosphamide or azathioprine
- Rituximab — a targeted therapy that removes certain immune cells
- Combination therapy for faster response
3. Treating the Underlying Cause
If acquired hemophilia is linked to:
- Autoimmune disease → treat the autoimmune condition
- Cancer → address the cancer with surgery, chemotherapy, or radiation
- Medication → stop the triggering drug
4. Supportive Care
Patients often need:
- Iron supplements or transfusions for anemia
- Physical therapy after large bleeds
- Wound care if skin or surgical bleeding occurs
Living with and Preventing Future Bleeding Episodes
Once the inhibitor is eliminated, many people fully recover — but recurrence is possible, especially if the underlying trigger persists.
Lifestyle Precautions
- Avoid contact sports and activities with high injury risk
- Use a soft-bristle toothbrush to prevent gum bleeding
- Inform all healthcare providers of your diagnosis
- Wear a medical alert bracelet stating “Acquired Hemophilia”
- Keep emergency contact information for your hematologist
Follow-Up and Monitoring
Even after remission, regular blood tests (aPTT, factor VIII activity) are recommended for at least 12–18 months to catch relapses early.
Conclusion
Acquired hemophilia may be rare, but its impact can be sudden, severe, and life-threatening if not recognized early. Unlike the inherited form, it can strike anyone — even those with no personal or family history of bleeding disorders. The key to survival and recovery lies in early diagnosis, rapid treatment, and careful follow-up.
By understanding the symptoms — like unexplained deep bruising, mucosal bleeding, or prolonged bleeding after minor injuries — both patients and healthcare providers can act faster. Modern treatments, from bypassing agents to targeted immune therapies, have dramatically improved outcomes, with many people achieving complete remission.
Living with acquired hemophilia requires vigilance, but it doesn’t mean giving up on a full, active life. With the right care team, personalized treatment plans, and preventive strategies, patients can manage their condition, reduce the risk of recurrence, and maintain quality of life.
If you or someone you know experiences unusual bleeding without explanation, seek immediate medical advice — and mention acquired hemophilia as a possibility. In rare diseases, awareness is the first line of defense.
Frequently Asked Questions
1. Can acquired hemophilia go away on its own?
In some mild cases, especially postpartum acquired hemophilia, the condition may resolve spontaneously within months. However, because bleeding can be unpredictable and dangerous, treatment is usually recommended to control symptoms and eliminate the inhibitor safely.
2. How long does treatment for acquired hemophilia usually last?
Most patients require several weeks to months of immunosuppressive therapy. The exact duration depends on how quickly the inhibitor disappears and whether an underlying condition is found and treated. Close monitoring is essential during and after treatment.
3. Is acquired hemophilia genetic?
No. Unlike hereditary hemophilia, acquired hemophilia is not passed down through families. It results from the immune system mistakenly attacking clotting factor VIII, often triggered by another condition or event.
4. Can acquired hemophilia come back after remission?
Yes, recurrence is possible — particularly if the underlying cause is not addressed or if the immune system becomes reactivated. This is why long-term follow-up with regular blood tests is important, even after symptoms disappear.
5. What should I do if I’m diagnosed with acquired hemophilia?
Seek care from a hematologist with experience in bleeding disorders. Follow your treatment plan closely, avoid high-risk activities that could lead to injury, and always carry medical identification. Inform any doctor or dentist about your diagnosis before undergoing procedures.
