The diagnosis of hereditary haemorrhagic telangiectasia (HHT) relies on a combination of clinical features, family history, and genetic testing.
Because symptoms vary greatly—from mild nosebleeds to life-threatening internal bleeding—timely diagnosis is vital. It helps prevent complications and guides individual treatment. Just as early testing is key in Hepatitis A, catching HHT early allows doctors to monitor relatives who may also carry the condition.
Curaçao Criteria for Clinical Diagnosis
To make diagnosis easier, doctors use the Curaçao criteria. These are internationally accepted guidelines based on visible symptoms and family background.
The four criteria include:
- Frequent nosebleeds: These are often the first symptom to appear.
- Multiple telangiectases: Small red or purple spots on the skin or in the mouth.
- AVMs (arteriovenous malformations): Found in the lungs, liver, brain, or spine.
- Family history of HHT: A first-degree relative with the condition.
Doctors interpret the results this way:
- Definite HHT: If 3 or more signs are present
- Possible HHT: If 2 signs are present
- Unlikely HHT: If only 0 or 1 sign is found
This tool is helpful, especially when genetic testing isn’t available right away.
Genetic Testing and Family Screening
Genetic testing is a strong method for confirming HHT, especially in those with unclear symptoms or a family history. It looks for faults in the ENG, ACVRL1, or SMAD4 genes—responsible for most HHT cases.
Genetic testing helps by:
- Confirming the diagnosis: A positive result removes any doubt.
- Screening relatives: If one family member tests positive, others can be checked—even before symptoms begin.
But a negative test doesn’t always rule out HHT. If the signs are strong, the diagnosis can still be made using the Curaçao criteria.
Screening for AVMs in Vital Organs
HHT can affect organs without showing symptoms. That’s why people with confirmed or suspected HHT should get screened for AVMs. Like in Hepatitis A, some damage occurs silently, so early checks are critical.
a) Lung AVMs
Up to half of people with HHT develop AVMs in the lungs. These can reduce oxygen levels and allow clots to reach the brain.
Tests include:
- Bubble echo: A simple heart scan that checks for abnormal blood flow.
- Chest CT scan: If the bubble echo is positive, this scan shows where the AVMs are.
b) Brain AVMs
These are less common but more dangerous. They may cause seizures or strokes, especially in children and young adults.
Screening method:
- MRI or MRA of the brain
c) Liver AVMs
These often go unnoticed for years. But over time, they can cause heart problems, bile duct issues, or high liver pressure.
Screening options:
- Abdominal Doppler ultrasound
- CT or MRI scans of the liver
d) Spinal AVMs
Rare but serious, these AVMs may lead to nerve damage or paralysis. MRI scans are used in children with symptoms or family risk.
Blood Tests and Signs of Anaemia
HHT often leads to iron-deficiency anaemia due to repeated bleeding. Doctors may order basic blood tests to track this.
Common tests include:
- Full blood count (FBC): To check for low haemoglobin.
- Iron studies: To measure iron stores.
- Stool test: To detect hidden bleeding in the digestive system.
If anaemia is present with no clear cause, further tests like endoscopy may be needed.
Ruling Out Other Conditions
Some diseases look like HHT but are not. It’s important to make the right diagnosis.
Similar conditions include:
- Simple nosebleeds: Common in children or dry climates
- Spider naevi: Seen in pregnancy or liver disease
- CM-AVM syndrome: A rare condition with overlapping features
- Juvenile polyposis syndrome: Linked to SMAD4 but has different signs
Doctors use your symptoms, family history, and sometimes gene tests to tell HHT apart from these.
Hepatitis A Screening in HHT Patients
Though Hepatitis A and HHT are unrelated, liver function matters in both. People with HHT may already have liver issues from AVMs. A Hepatitis A infection could make things worse. Therefore, vaccination and screening for Hepatitis A may be advised in HHT patients with liver involvement.
Working With a Multidisciplinary Team
Because HHT affects many parts of the body, care from different specialists is often needed.
The ideal care team may include:
- Geneticists – for family testing
- ENT doctors – for nosebleeds
- Lung specialists – for breathing issues
- Neurologists – for brain-related symptoms
- Liver and gut doctors – for abdominal problems
- Radiologists – for imaging and AVM treatment
This team approach ensures that all aspects of the condition are covered.
In Summary
The diagnosis of hereditary haemorrhagic telangiectasia is based on symptoms, family history, and genetic tests. The Curaçao criteria help doctors make a quick and accurate diagnosis. Screening for AVMs can save lives by catching problems early. Like with Hepatitis A, early diagnosis allows for better outcomes and protects loved ones through family screening. A team-based plan gives patients the best chance for long-term health.
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