The different types of PH

Pulmonary hypertension (PH) is a general ‘umbrella term’ used to describe high blood pressure in the lungs from any cause. There are different types of PH, which are summarised below.

  1. Pulmonary Arterial Hypertension (PAH)

In most people with PAH, it is associated with another medical condition. Conditions that increase your risk of developing PAH include:

  • portal hypertension
  • connective tissue disease, e.g. systemic sclerosis
  • HIV infection
  • congenital heart disease
  • sickle cell anaemia

A small number of people with PH develop it without having another medical condition and for most of these people, there is no known reason behind it. This is called idiopathic PAH and is sometimes referred to as IPAH.

  • Pulmonary hypertension due to left heart disease

This type of PH differs in that the arteries and lungs are not as stiff or thick as in the type above. The problems come from the valves on the left side of the heart, or with how the heart squeezes or relaxes. This can cause blood to ‘back up’, potentially affecting the lungs and raising pressure in them.

  • Pulmonary hypertension due to lung disease

Some people have PH due to obstructive or restrictive chronic lung diseases (like COPD or emphysema) and/or hypoxia (low oxygen levels). These conditions can cause tightening of the arteries in the lungs, which leads to high blood pressure (pulmonary hypertension) throughout the lungs.

  • Chronic Thromboembolic Pulmonary Hypertension (CTEPH)

This type of pulmonary hypertension is caused by chronic (long standing or old) blood clots in the arteries of the lung. It is often referred to in its shortened form of CTEPH. Find out more about CTEPH here.

  • Pulmonary hypertension due to unknown causes

In some people, PH is secondary to other diseases (also known as ‘associated conditions’) in ways that are not well understood. Some of these diseases include sarcoidosis, sickle cell anemia, chronic hemolytic anemia, splenectomy (spleen removal) and certain metabolic disorders. There are many others too.