Abdul Mannan/LinkedIn

Jan 26, 2026, 04:59

Abdul Mannan: BDUC – 4 Letters That Make Many Haematologists Uncomfortable

Abdul Mannan, Consultant Haematologist at Betsi Cadwaladr University Health Board, shared on LinkedIn:

”BDUC. Four letters that make many haematologists uncomfortable.

Bleeding Disorder of Unknown Cause. The patient bleeds. Your tests are normal.

Now what?

I’ve developed a 4-step systematic approach to navigate this clinical challenge:

Step 1: The Gatekeeper

Apply ISTH-BAT Score (≥4 men, ≥6 women, ≥3 children)

If normal, stop. No hemostatic workup needed.

Check for hypermobility syndromes and medication culprits (NSAIDs, SSRIs, garlic, ginkgo)

Step 2: Rule Out Common Disorders

CBC, blood film, routine coagulation, VWF screen (≥0.50 IU/mL required)

First-line platelet function (LTA with agonists)
Remember: Inflammation masks mild VWD and Haemophilia A

Step 3: Hunt for Rare Disorders

If Step 2 is normal but bleeding history is convincing, test FXIII (delayed wound healing!) and Factors II, V, VII, IX, XI, X

Consider dense granule deficiency with ATP:ADP ratio or electron microscopy

Step 4: Confirm BDUC

High BAT score + completely normal Steps 2 and 3 equals BDUC confirmed

Test fibrinolytic defects only if delayed bleeding or umbilical stump issues (ASH 2025)

TEG, ROTEM, NGS? Not standard of care. Low yield.

Two pitfalls I see repeatedly: Overlooking iron deficiency (worsens platelet function)

Testing FVIII/VWF during pregnancy or inflammation (falsely normal)

The visual flowchart is in the comments below.

What’s your approach when bleeding history is strong but labs are normal?”

Abdul Mannan: BDUC - 4 Letters That Make Many Haematologists Uncomfortable

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