Pulmonary hypertension with unclear or multifactorial etiologies
Group 5 of WHO classification
Hematologic disorders
• myeloproliferative disorders
• chronic haemolytic anaemia
• Splenectomy
Systemic disorders
• vasculitis
• sarcoidosis
• pulmonary Langerhans cell histiocytosis
• lymphangioleiomyomatosis
• neurofibromatosis
Metabolic disorders
• glycogen storage disease
• Gaucher disease
• thyroid disorders
miscellaneous conditions
• tumor obstruction
• Segmental pulmonary hypertension
• mediastinal fibrosis
• chronic renal failure on dialysis
Sources
1. Clinical features and diagnosis of pulmonary hypertension of unclear etiology in adults https://www.uptodate.com/contents/clinical-features-and-diagnosis-of-pulmonary-hypertension-of-unclear-etiology-in-adults?search=%20pulmonary%20hypertension&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
2. Pulmonary Arterial Hypertension https://emedicine.medscape.com/article/303098-overview