Home H Cardiovascular Conditions Hereditary hemorrhagic telangiectasia: Overview, Symptoms, Diagnosis, and Treatment Options

Hereditary hemorrhagic telangiectasia: Overview, Symptoms, Diagnosis, and Treatment Options

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Hereditary hemorrhagic telangiectasia (HHT) is a genetic condition that makes certain blood vessels form abnormally. Many people first notice frequent nosebleeds or tiny red spots on the lips or fingertips, but the condition can also involve blood vessels in the lungs, brain, liver, and digestive tract. That combination is why HHT can feel unpredictable: one person may mainly deal with nuisance bleeding, while another faces risks that are silent until a complication occurs.

The most empowering part of HHT care is that it is screenable and treatable. When clinicians look for hidden vessel connections early—and treat iron deficiency before it becomes severe—many serious outcomes can be prevented. This article explains what HHT is, why it happens, who is at higher risk for complications, how symptoms typically appear, what diagnostic and screening steps matter most, and how treatment and day-to-day management usually work.

Table of Contents

What HHT does and why it matters

HHT (also called Osler–Weber–Rendu syndrome) is best understood as a blood-vessel wiring problem. In healthy tissue, blood flows from arteries into tiny capillaries and then into veins. Capillaries are the “pressure reducers” that protect small vessels from bursting. In HHT, some capillary networks do not form properly, leading to two common vessel patterns:

  • Telangiectasias: small, surface-level widened vessels that often appear on the nose lining, lips, tongue, face, and fingertips. These are fragile and bleed easily.
  • Arteriovenous malformations (AVMs): larger direct connections between arteries and veins. AVMs can occur inside organs, most notably the lungs, brain, and liver.

This difference matters because telangiectasias mainly create recurrent bleeding, while AVMs can create silent, high-impact risks. A lung AVM, for example, can allow tiny clots or bacteria to bypass the lungs’ normal filtering system and travel directly to the brain. That is why some people with HHT face a higher risk of stroke or brain abscess, even if their nosebleeds are mild.

Where HHT tends to show up

  • Nose and mouth: bleeding from nasal telangiectasias is common and often worsens with age.
  • Digestive tract: telangiectasias in the stomach or intestines can cause slow blood loss that you may not see.
  • Lungs: pulmonary AVMs can cause low oxygen levels or neurological complications.
  • Brain: vascular malformations can bleed or trigger seizures in a subset of patients.
  • Liver: vascular malformations may lead to high-output heart strain or bile duct problems in more severe cases.

Why the same diagnosis looks different in different people

HHT is variable. Two relatives with the same gene change can have very different symptom burdens, because the number, location, and size of abnormal vessels differ. Symptoms can also evolve over decades. Many people shift from “mostly nosebleeds” to “nosebleeds plus anemia,” or discover a lung AVM only after targeted screening.

A useful way to organize HHT care is to treat it as two tracks at once:

  1. reduce day-to-day bleeding and anemia, and
  2. proactively find and manage internal AVMs before they cause emergencies.

That second track—screening—often makes the biggest difference in long-term safety.

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Causes, genetics, and risk factors

HHT is usually caused by an inherited change in genes that guide how blood vessels grow, repair, and stabilize. The result is a lifelong tendency to form telangiectasias and, in some people, AVMs in internal organs.

Inheritance pattern and family implications

HHT is typically autosomal dominant, meaning:

  • If a parent has HHT, each child has a 50% chance of inheriting it.
  • Men and women are affected equally.
  • Symptoms may appear later in life, so a child can carry HHT before obvious signs appear.

Because internal AVMs can be present even when the skin looks normal, family risk is not only about “who gets nosebleeds.” In many families, the safest approach is to identify who carries the condition and ensure appropriate screening, especially for lung and brain vascular malformations.

Genes commonly involved

Several genes are strongly linked to classic HHT. While the details are complex, the practical takeaway is straightforward: these genes influence signals that tell vessel-lining cells how to form normal capillary networks. When that signaling is disrupted, vessels may form fragile surface clusters or direct artery-to-vein shortcuts.

Some gene patterns are associated with different organ involvement tendencies, but genetics does not replace screening. Two people with the same gene variant can still have different AVM locations and sizes.

Situations that can increase symptom burden

Genes create susceptibility, but everyday factors can influence how symptoms show up:

  • Dry air and nasal irritation: often worsens epistaxis (nosebleeds), especially in winter or with indoor heating.
  • Nasal inflammation: allergies, chronic sinus irritation, or frequent colds can increase bleeding frequency.
  • Medications that affect bleeding: aspirin, many anti-inflammatory medicines, and prescription blood thinners can worsen bleeding in some patients (though blood thinners may still be necessary for other medical reasons).
  • Iron depletion: once iron stores drop, a person can feel much worse even if bleeding volume hasn’t changed. Treating iron deficiency often improves symptoms faster than people expect.
  • Pregnancy and postpartum: blood volume and circulation change significantly, and untreated lung AVMs can become more hazardous during pregnancy.

Who is at higher risk for complications

People may face higher complication risk when they have:

  • A known lung or brain AVM
  • Unexplained low oxygen levels
  • Severe anemia or repeated transfusion needs
  • Liver vascular malformations with signs of heart strain
  • A family history of stroke, brain hemorrhage, or early unexplained neurologic events

A practical insight: risk is not always obvious from the outside. A person with mild nosebleeds may still have a clinically important lung AVM, while someone with frequent nosebleeds may never develop organ AVMs. That is why HHT care is strongest when it combines symptom control with structured screening rather than relying on symptom severity alone.

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Symptoms and complications to recognize

HHT symptoms tend to fall into two categories: bleeding-related problems you can notice and track, and AVM-related risks that may be silent until a major event occurs. Understanding both helps you respond appropriately—without panic, but without dismissal.

Common bleeding-related symptoms

  • Recurrent nosebleeds: often the earliest and most common symptom. Bleeds can be frequent and brief or less frequent but heavy. Many people underestimate total blood loss because each episode feels “small.”
  • Visible telangiectasias: tiny red or purple spots that often appear on lips, tongue, face, inside the nose, or fingertips. They may blanch when pressed.
  • Iron deficiency and anemia: a major driver of fatigue. Symptoms can include low energy, shortness of breath with exertion, headaches, dizziness, poor concentration, restless legs, and a racing heartbeat with activity.

Digestive tract bleeding can be especially deceptive. Telangiectasias in the stomach or intestines often bleed slowly, so you may not see red blood. Clues include low iron despite “not bleeding much,” dark stools, or needing repeated iron infusions.

Symptoms that may point to lung AVMs

Some people have no symptoms, but possible clues include:

  • Unexplained low oxygen levels or shortness of breath out of proportion to fitness
  • Migraines in some patients
  • Prior stroke-like symptoms without a clear cause

A key danger of lung AVMs is paradoxical embolization—particles that would normally be filtered by lungs reach the brain. That risk can show up as stroke or brain abscess, sometimes in people who felt well days earlier.

Symptoms that may point to brain vascular malformations

Brain vascular malformations may be silent, but red flags include:

  • New seizures
  • Sudden severe headache
  • Weakness, numbness, speech difficulty, balance trouble, or vision changes
  • Unexplained fainting or severe confusion

Symptoms that may point to liver involvement

Liver vascular malformations can increase blood flow demands on the heart. Possible clues:

  • Worsening shortness of breath, swelling, or fatigue consistent with heart strain
  • Abdominal discomfort, enlarged liver, or abnormal liver blood tests
  • Signs of portal hypertension in advanced cases

Complications to take seriously

The highest-impact complications typically relate to:

  • Severe anemia: which can strain the heart and reduce safety during infections, pregnancy, or surgery
  • Stroke or brain abscess: often linked to untreated lung AVMs in some patients
  • Major bleeding events: less common than nosebleeds, but serious when they involve the brain or gastrointestinal tract

A practical tool many patients find useful is a “bleeding and energy log.” Track nosebleed frequency, average duration, and whether it disrupts sleep; record fatigue level and iron labs when available. Patterns often reveal that iron depletion—not only bleeding frequency—is the turning point in quality of life. That clarity helps clinicians choose the right next step, from simple nasal care to procedural or systemic therapy.

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How HHT is diagnosed and screened

Diagnosis is based on clinical features, family history, and sometimes genetic testing. Screening then focuses on finding organ AVMs early—because waiting for symptoms can be risky.

Clinical diagnosis: the Curaçao criteria

Clinicians commonly use four criteria:

  • Recurrent spontaneous nosebleeds
  • Multiple telangiectasias at typical sites (lips, mouth, fingers, nose)
  • Visceral involvement (lung, brain, liver AVMs, or gastrointestinal telangiectasias)
  • A first-degree relative with HHT

When several criteria are present, the diagnosis becomes more certain. In children, diagnosis may be less obvious because telangiectasias can appear later; this is where genetics and screening can be especially helpful.

Genetic testing: what it can and cannot do

Genetic testing can:

  • Confirm HHT when symptoms are incomplete
  • Identify the family-specific variant, enabling efficient testing of relatives
  • Support earlier screening decisions in children

However, a negative test does not always exclude HHT if clinical features strongly fit. Clinicians may still recommend screening based on symptoms and family history.

Screening: the “silent risk” checklist

A typical screening plan prioritizes areas where intervention can prevent major harm:

  • Lung AVM screening: often begins with a bubble echocardiogram (contrast echo) to detect right-to-left shunting, followed by chest imaging if needed to map treatable AVMs.
  • Brain screening: brain MRI is commonly used, especially in children, and may be considered in adults depending on local practice and individual risk factors.
  • Anemia and iron status: periodic blood counts and iron studies help detect chronic bleeding early, even when stools look normal.
  • Liver evaluation: often targeted to adults or those with symptoms, because liver vascular malformations can affect heart function and circulation.

Rescreening and life-stage planning

Screening is not always one-time. Plans vary by age and findings, but many clinicians consider:

  • Repeat lung screening at intervals when initial screening is negative, with closer attention during growth years and around pregnancy planning.
  • Individualized decisions about repeat brain imaging, balancing benefit with the lower likelihood of new lesions in adulthood compared with childhood.

What a good diagnosis visit should produce

Even in a busy clinic, the goal should be a clear, written plan:

  • Diagnosis status (clinical criteria, genetic result if known)
  • Which organ screenings have been done, when, and what was found
  • The iron/anemia management plan with lab targets
  • When to recheck, and which symptoms should trigger earlier review

If you only remember one thing: HHT care is safest when it treats nosebleeds and iron deficiency seriously and screens for organ AVMs proactively. People tend to regret the screenings they skipped more than the screenings they did “just in case.”

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Treatment options and what to expect

There is no single cure for HHT, but many symptoms and complications are treatable. Most specialists use a stepwise approach: start with the least invasive option that reasonably matches the severity and escalate based on objective burden (bleeding, iron needs, organ findings, and quality of life).

Nosebleed treatment: a practical ladder

  1. Moisture and protection (baseline for almost everyone)
  • Saline sprays or gels, humidification at night, and gentle nasal care
  • Treat allergic inflammation and avoid drying nasal products when possible
  1. Targeted medications (when conservative care is not enough)
  • Antifibrinolytic therapy (such as tranexamic acid) may reduce bleeding in selected patients, especially when nosebleeds drive anemia. Clinicians balance benefit against clotting risk based on personal history.
  1. Office or operating-room procedures (for persistent bleeding)
  • Laser or other ablative techniques can treat visible nasal telangiectasias
  • Sclerotherapy may help in certain settings
  • For severe cases, septodermoplasty or, rarely, nasal closure may be considered in specialized hands

A useful expectation: nosebleed treatments often work best when paired with consistent daily moisture. Procedures can reduce the “hot spots,” but dryness and irritation can still trigger bleeding elsewhere.

Iron deficiency and anemia: treat early and track

Iron repletion is central:

  • Oral iron may work for mild deficiency if tolerated; many people do better with lower-dose or every-other-day schedules to reduce stomach side effects.
  • IV iron is common when oral iron fails, anemia is more severe, or ongoing losses exceed absorption capacity.
  • Blood transfusion is typically reserved for urgent situations or severe anemia with symptoms.

Clinicians often monitor hemoglobin and iron stores, not just hemoglobin. Many patients feel better when iron stores are replenished even if hemoglobin was “borderline.”

Gastrointestinal bleeding management

When gut telangiectasias drive iron loss:

  • Endoscopic treatments (such as localized coagulation techniques) can reduce bleeding from reachable lesions.
  • Systemic therapies may be considered for recurrent, transfusion-dependent bleeding when local approaches are insufficient.

Treating organ AVMs

  • Lung AVMs: embolization (blocking the abnormal vessel from inside the bloodstream) is commonly used when AVMs meet size and risk criteria. This can reduce the risk of stroke and brain abscess in appropriate patients.
  • Brain vascular malformations: management is individualized; some lesions are monitored, while others are treated via surgery, endovascular therapy, radiosurgery, or a combination depending on risk features.
  • Liver vascular malformations: treatment may involve managing heart strain and complications. In carefully selected severe cases, systemic anti-angiogenic therapy may be considered by experienced teams.

Systemic therapies for severe bleeding

For patients with high bleeding burden (frequent iron infusions, repeated transfusions, or severe symptoms), clinicians may consider systemic agents that target abnormal vessel growth signaling. These can be meaningful for selected patients but require careful screening and monitoring because they can have serious side effects and are not appropriate for everyone.

A practical, patient-centered way to judge treatment success is to ask three questions over time:

  • Are nosebleeds less disruptive (sleep, work, travel)?
  • Is iron easier to maintain with fewer infusions or transfusions?
  • Are organ risks being actively monitored and addressed?

Those outcomes often matter more than any single lab value.

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Management, prevention, and when to seek care

HHT management is most effective when it is proactive, routine-based, and written down. Many patients do best with a simple “care map” that covers daily prevention, scheduled screening, and clear instructions for urgent situations.

Day-to-day habits that reduce bleeding burden

  • Nasal care routine (think of it as prevention, not rescue):
  • Humidify the bedroom during dry seasons
  • Use saline gel or spray consistently
  • Avoid nose picking and aggressive nose blowing
  • Treat allergies and chronic nasal inflammation
  • Iron strategy you can follow:
  • Know your target hemoglobin range and iron goals
  • Have a plan for when symptoms return (fatigue, breathlessness, restless legs)
  • Keep track of how often you need oral iron, IV iron, or transfusions

A helpful concept is the “bleeding budget.” Even small daily or weekly losses can exceed what diet and absorption can replace. If your iron needs keep rising, the goal is not to “try harder” with food—it is to adjust treatment intensity.

Prevention strategies for organ-related complications

  • Keep lung AVM screening up to date. Treatable lung AVMs are one of the most preventable sources of serious neurological complications in HHT.
  • Ask about procedure precautions. Some people with right-to-left shunting may need special precautions for procedures that can introduce bacteria into the bloodstream (such as certain dental work). Your care team should tell you what applies to your anatomy and history.
  • Be cautious with scuba diving or unpressurized high-altitude exposure if lung AVMs are present or suspected. Changes in pressure can increase risk in some right-to-left shunt situations; personalized advice matters.

Pregnancy planning and special situations

Many people with HHT have safe pregnancies, but planning is important:

  • Discuss pregnancy early with an HHT-experienced team.
  • Ensure lung AVM screening is up to date before pregnancy when possible.
  • Have a clear plan for anemia prevention, since iron needs often increase during pregnancy.

Children in HHT families also benefit from thoughtful planning. Because signs can appear later, genetic testing (when available) and age-appropriate screening can prevent missed internal AVMs.

When to seek urgent or emergency care

Get emergency help immediately for:

  • Sudden weakness, speech trouble, vision changes, new seizure, or severe sudden headache
  • Heavy bleeding causing fainting, chest pain, or shortness of breath at rest
  • Vomiting blood or black, tarry stools with weakness or dizziness

Seek prompt medical evaluation (same day or within 24–48 hours) for:

  • A major shift in nosebleed pattern (longer, more frequent, harder to stop)
  • New dark stools, unexplained fatigue, or a steep drop in exercise tolerance
  • New or worsening breathlessness, especially if oxygen levels are low

A simple “one-page” summary that improves care

Many patients keep a one-page note that includes:

  • Diagnosis status and genetic result (if known)
  • Dates and results of lung and brain screening
  • Current iron plan and recent lab values
  • Medications that worsen bleeding or affect clotting
  • Specialist contacts and the nearest experienced center

In HHT, small details—like a documented screening result or a clear iron plan—can prevent big problems. The goal is not to live in fear; it is to make risks visible, manageable, and appropriately monitored.

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References

Disclaimer

This article is for educational purposes and does not replace medical advice, diagnosis, or treatment from a licensed clinician. Hereditary hemorrhagic telangiectasia can involve internal blood vessel malformations that may cause serious complications without obvious symptoms. If you develop sudden neurologic symptoms (such as weakness, trouble speaking, vision changes, seizure, or a severe sudden headache) or heavy bleeding with fainting or shortness of breath, seek emergency care immediately. Screening schedules, procedure precautions, and medication choices must be individualized by your healthcare team.

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