Pathological changes occur in dengue haemorrhagic  Fever ( DHF):
PATHOLOGIC CHANGES The predominant organ Changes in DHF are due to:

Focal haemorrhages and congestion;
Increased vascular permeability resulting in oedema in different organs;
Coagulopathy with thrombocytopenia; and
Haemoconcentration.
Focal haemorrhages and congestion.
Coagulopathy with thrombocytopenia.
Haemoconcentration.
All of the above.