Types of pulmonary hypertension

There are five main types of pulmonary hypertension:
• Pulmonary arterial hypertension
• Pulmonary hypertension with left heart disease
• Pulmonary hypertension associated with lung disease and/or hypoxaemia
• Pulmonary hypertension due to thrombotic and/or embolic disease
• Pulmonary hypertension due to miscellaneous causes directly affecting the pulmonary vasculature

Pulmonary arterial hypertension (PAH)
• Idiopathic (IPAH)
• Familial (FPAH)
• Associated (APAH) with:
- Connective tissue disease
- Congenital heart disease
- Portal hypertension
- HIV
- Drugs and toxins
Definite: fenfluramine, aminorex, toxic rapeseed oil
Very likely: amphetamines, L-tryptophan, cocaine, meta-amphetamines
Possible: chemotherapy, phenylpropanolamine, St John's Wort
- Other
Thyroid disease, glycogen storage disease, Gaucher’s disease, hereditary haemorrhagic telangiectasia, haemoglobinopathies, myeloproliferative disorders, splenectomy
• PAH with significant venous and/or capillary involvement
- Veno-occlusive disease
- Capillary haemangiomatosis
• Persistent pulmonary hypertension of the newborn

Pulmonary hypertension with left heart disease*
• Left-sided atrial or ventricular disease
• Left-sided valvular heart disease

Pulmonary hypertension associated with lung disease and/or hypoxaemia*
• Chronic obstructive pulmonary disease (COPD)
• Interstitial lung disease
• Sleep disorders
• Alveolar hypoventilation
• Chronic exposure to high altitude
• Developmental abnormalities

Pulmonary hypertension due to thrombotic and/or embolic disease
• Thromboembolic obstruction of proximal pulmonary arteries
• Thromboembolic obstruction of distal pulmonary arteries
• Non-thrombotic pulmonary embolism (tumour, parasites, ova, foreign material)

Pulmonary hypertension due to miscellaneous causes directly affecting the pulmonary vasculature
• Sarcoidosis
• Histiocytosis X
• Lymphangiomatosis
• Compression of pulmonary vessels
- Tumours
- Adenopathy
- Fibrosing mediastinitis

* Patients falling into these groups do not normally require referral because the management of pulmonary hypertension is primarily the management of the underlying condition.