What is Pulmonary Hypertension?
Pulmonary hypertension (PH) is a rare progressive disease (may or may not be genetic) in which blood pressure is elevated in the lung arteries, affecting the lungs and the right side of the heart. Statistically, more female patients are reported afflicted with some variation of this disease than male patients. Each year, 10 to 15 individuals per million in the US are reported to have this condition. Pulmonary hypertension is characterized by the narrowing, swelling, or hardening of the blood vessels (pulmonary artery) that carry blood from the lower right chamber of the heart to the lungs. Sometimes these blood vessels may be partially or entirely blocked due to some medical conditions. It creates difficulties in the normal flow of blood. The heart has to exert more to pump the blood through these narrow and damaged blood vessels which successively weakens the heart muscles and may lead to heart failure.
Pulmonary blood pressure is typically lower than systemic (body) blood pressure. Normal pulmonary arterial pressure is 8-20 mm Hg at rest. If the pressure is more than 25 mmHg at rest or 30 mmHg during activity, it is higher than the threshold and is identified as pulmonary hypertension.
Causes of Pulmonary Hypertension
Your genetics or alternative medical conditions can be responsible for pulmonary hypertension. Some medical conditions may injure or cause partial or complete blockages in the blood vessels of the pulmonary arteries. The cause of it is not always understood or anticipated. However, the different types of pulmonary hypertension give us a broader idea of the causes of this disease.
Types of Pulmonary Hypertension
The World Health Organization (WHO) recently updated the classification for pulmonary hypertension diagnosis based on the cause of the disease in 2013 in Nice, France. Today, the WHO classifies pulmonary hypertension into five categories:
Group 1: Pulmonary arterial hypertension
Pulmonary arterial hypertension (PAH) is related to the narrowing or swelling of the arteries within the lungs.
Reason for PAH are:
- Inherited pulmonary hypertension: a genetic mutation passed down in the family line
- Idiopathic pulmonary arterial hypertension
- Connective tissue diseases like scleroderma or lupus,
- Congenital heart problems (heart problems present since birth)
- High blood pressure in the liver
- Infections like schistosomiasis and sickle cell anemia.
- Pulmonary veno-occlusive disease (PVOD)
- Pulmonary capillary hemangiomatosis (PCH)
- Persistent pulmonary hypertension of the newborn (PPHN)
Group 2: Pulmonary hypertension due to left heart disease
Prolonged problems with the left side of the heart can lead to damages in the arteries going to the lungs from the heart and cause pulmonary hypertension. PH due to left heart disease results from:
- Left ventricular diastolic dysfunction where the heart cannot properly relax during the diastole to allow enough blood to flow in
- Left ventricular systolic dysfunction in which case the heart cannot pump blood effectively
- Valvular disease caused when the mitral or aortal valves of the left side of the heart have leakages and blood escapes
Group 3: Pulmonary hypertension due to lung disease and chronic hypoxia
This group includes pulmonary hypertension resulting from lung diseases and is caused by:
Group 4: Pulmonary hypertension due to blood clots in the lungs
This refers to pulmonary hypertension caused by blood clots obstructing the pulmonary arteries and occurs due to:
Group 5: Pulmonary hypertension due to blood and other disorders
This last group Group 5 includes uncommon and extremely rare causes of pulmonary hypertension that do not fit into any of the other four groups, like:
- Blood disorders such as polycythemia vera and thrombocythemia
- Diseases like sarcoidosis and histiocytosis
- Anatomical causes such as glycogen storage diseases and thyroid disorders
- Existing conditions such as chronic kidney failure or tumors obstructing pulmonary arteries
What are the Symptoms of Pulmonary Hypertension?
Pulmonary hypertension can develop slowly, without any visible or discernible signs and symptoms. When symptoms do occur, they typically get attributed to asthma, other lung or heart conditions, or breathing disorders since the symptoms are similar.
Early symptoms include:
- Shortness of breath during routine activity (dyspnea)
- Chest pain
- Rapid heartbeat
- Pain in the upper right side of the abdomen
- Decreased appetite
Later symptoms include:
- Feeling light-headed, especially during physical activity
- Swelling in the ankles or legs
- Bluish lips or skin
Medical Attention and Diagnosis of Pulmonary Hypertension
Your doctor may ask about your symptoms, risk factors, other pre-existing medical conditions, and family history to diagnose and determine whether you have pulmonary hypertension. Having a family member with pulmonary hypertension increases your risk of developing the disease as in some types of PH, it is genetic. Your doctor may recommend tests and procedures to diagnose PH and discover its cause and severity. Finding the root cause may include a chest CT scan, chest MRI, lung function tests, polysomnogram (PSG), lung ventilation/perfusion scan, and blood tests.
Common diagnostic tests include:
- Chest X-ray,
- Electrocardiogram (EKG)
- Catheterization of the right heart.
If you are diagnosed with pulmonary hypertension, your doctor will come up with a treatment plan based on the cause of the disease. There is no cure for pulmonary hypertension but you can live an active, fulfilling life by working with your doctor to manage your symptoms. Your doctor may recommend healthy lifestyle changes, medicines or other treatments to keep your symptoms in control and to avoid them getting worse. It is essential to follow your specific treatment plan as suggested and get regular checkups to monitor your condition. Being vigilant can slow down the progression of the disease and may improve your condition.
Risk Factors for Pulmonary Hypertension
Some risk factors for developing pulmonary hypertension are:
- Age: older people have higher possibilities of developing this than younger adults
- Family history of PH
- Other medical conditions like HIV, liver diseases, heart complaints
- Illegal drugs
- Living in higher altitude
- Gender: Women are twice more susceptible to develop pulmonary hypertension than men
Complications in Pulmonary Hypertension
Complications may include:
- Arrhythmias and bundle branch blocks of the heart
- Blood clots in the pulmonary arteries
- Hemorrhage in the lungs
- Heart failure (specifically right ventricular failure)
- Liver damage from increased pressure in the heart
- Pericardial effusion
- Pregnancy complications that may be critical for the mother and baby