To understand what PH is, it first helps to understand a bit about the circulatory system. As shown in the figure, the heart pumps oxygen-poor blood to the lungs so the blood can take up oxygen. Blood that is oxygen-poor is normally shown on diagrams as blue, whereas oxygen-rich blood returning from the lungs is normally shown in red.

The heart and circulatory system

During periods of exercise, the heart beats more quickly to get more oxygen to the muscles. At the same time, the blood vessels carrying blood to the lungs (the pulmonary arteries) expand to allow more blood through. The pulmonary arteries do this by stretching slightly. In a person with PH, the walls of the pulmonary arteries are thicker, so are less able to stretch.

The pulmonary artery in a healthy person

The pulmonary artery in a person with PH

In a person with PH, because the pulmonary arteries are less able to stretch, the heart has to work harder to pump blood to the lungs. If the heart has to work harder than usual over a long period of time (months or years), it begins to work less effectively.

Symptoms

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).

What is the outlook for people with PH?

The outlook for a person with PH is different for each person. This depends on a number of things:

• How severe your PH is
• Associated conditions
• Overall general health
• Your lifestyle
• Response to treatments.

Overall, the outlook for people with PH has improved dramatically over the last 20 years. This is because of the introduction of new, effective treatments for PH.

You should talk to your consultant if you would like to know more about what to expect.

What treatments are available for people with PH?

There are several different treatments available for PH. These include conventional treatments (often called supportive or background therapy) and targeted treatments.

Some treatments for PH can help improve symptoms and some may slow disease progression and reverse damage to the heart and lungs.