Pulmonary hypertension (PH) is high blood pressure (hypertension) in the blood vessels (pulmonary arteries) that supply the lungs
PH is a rare condition that affects patients of all ages. There are various forms of PH, including idiopathic pulmonary arterial hypertension (PAH), which occurs for no apparent reason, and is progressive.
Other forms of PH are linked to cardiovascular and lung conditions. For patients in this category, treating the primary condition that is causing the PH may prevent further harm.
For PH patients, the lining of the pulmonary arteries grow thicker because of faulty cell function, causing blood pressure to rise abnormally.
By reducing blood flow, PH makes it harder for the right side of the heart to pump blood. It is important to treat PH as over time, the right side of the heart can become weaker, leading to heart failure and death.
There are five types of Pulmonary Hypertension
Not all Pulmonary hypertension (PH) is the same. The World Health Organisation has defined five types (or groups) of Pulmonary hypertension.
Group 1: Pulmonary arterial hypertension (PAH)
Group 1 refers to pulmonary arterial hypertension (PAH), this is caused when the arteries in the lungs become narrowed, thickened or stiff. The right side of the heart has to work harder to push blood through these narrowed arteries. The extra stress can cause the heart to lose its ability to pump enough blood through the lungs to meet the needs of the rest of the body.
There are different types of PAH. Idiopathic PAH (IPAH) is PAH that occurs without a clear cause. Heritable PAH (HPAH is linked to genes that are inherited from family members. Congenital heart disease, liver disease, HIV and connective tissue diseases — such as scleroderma and lupus, can also cause PAH to develop. PAH can also develop as a result of past or present drug use. Treatment options for PAH are available however, there is currently no cure.
Group 2: Pulmonary hypertension due to left heart disease
Group 2 includes PH due to left heart disease. In this group of PH, the arteries and lungs are not as thick or stiff as with PAH (Group 1). There are, however, problems with how the heart squeezes or relaxes, or problems with the valves on the left side of the heart. As a result of this, the left heart is unable to keep up with the blood returning from the lungs. This causes an excess of blood which raises pressure in the lungs. This is the most common type of PH.
Group 3: Pulmonary hypertension due to lung disease
Group 3 includes PH due to chronic lung disease and/or hypoxia (low oxygen levels). These lung diseases include obstructive lung disease where the lung airways narrow and make it harder to exhale (e.g. COPD or emphysema); restrictive lung disease in which the lungs have a tough time expanding when one inhales (e.g. interstitial lung disease or pulmonary fibrosis); sleep apnea; and living in an area of high altitude for a long period of time. Arteries in the lungs tighten so that blood can only go to areas of the lungs that are receiving the most air and oxygen. This tightening leads to high blood pressure throughout the lungs.
Group 4: Pulmonary hypertension due to chronic blood clots in the lungs
Group 4 is referred to as chronic thromboembolic pulmonary hypertension (CTEPH). When the body is not able to dissolve a blood clot in the lungs, CTEPH can occur. This can lead to scar tissue in the blood vessels of the lungs, which blocks normal blood flow and causes the right side of the heart to work harder. This type of PH can potentially be cured through pulmonary thromboendarterectomy surgery to remove the blood clots. While this form of PH can potentially be cured, unfortunately, not all CTEPH patients are eligible for this surgery. There is treatment available if the patient is not a candidate for the PTE surgery or if PH remains following surgery.
Group 5: Pulmonary hypertension due to unknown causes
Group 5 is where PH is secondary to other diseases in ways that are not completely understood. These associated conditions include, but are not limited to, sarcoidosis, sickle cell anemia, chronic hemolytic anemia, splenectomy (spleen removal) and certain metabolic disorders.
Symptoms of pulmonary hypertension
The NHS lists symptoms of pulmonary hypertension as:
- Shortness of breath (dyspnea) especially during exercise
- Chest pain
- Fainting episodes
- Racing heartbeat
- Swelling in the legs, ankles, feet or abdomen
For most patients, the exact cause of PAH is unknown. Although treatable, there is no known cure for the disease.
The progressive nature of this disease, particularly for patients with PAH, means that an individual may experience only mild symptoms at first. They will eventually require treatment and medical care to maintain a reasonable quality of life.
Research The Dinosaur Trust is funding is already making a difference! We have long been supporters of Great Ormond Street Hospital and on advice from Shahin Moledina, Lead Clinician for the National Paediatric Pulmonary Hypertension Service UK, The Dinosaur Trust now funds a Research Nurse and Research Assistant at Great Ormond Street Hospital.
To read more about our past and present research projects head over to the research section of our website.
Find out more about information about pulmonary arterial hypertension (PAH) treatments.
The ultimate goal of The Dinosaur Trust is to fund research to find better treatments and eventually a cure for pulmonary arterial hypertension. Some of the research projects that we fund also have the potential to benefit those affected by other forms of pulmonary vascular disease and pulmonary hypertension.
Disclaimer: It is not the intention of The Dinosaur Trust to provide medical advice, diagnosis or treatment. This content is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your Doctor or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on our pages or on a website.