Pulmonary hypertension (PH) is a serious medical condition, and should not be confused with hypertension (high blood pressure).
The disease causes high blood pressure in the blood vessels connecting the heart and lungs (pulmonary arteries).
PH is very rare, with around 7,000 people living with a diagnosis in the UK. It can affect anyone, regardless of age or ethnic background. It is more common in women than in men.
The main symptom of PH is breathlessness. This is the symptom that people will normally notice first. Other symptoms may include dizziness, feeling faint, swelling of the feet or ankles, and chest pain (particularly during exercise).
This simple animation was designed to help patients (and the general public) understand more about PH: