What Causes Pulmonary Hypertension?

Introduction

Pulmonary Hypertension (PH) is a grave disease in which the blood pressure within the arteries in the lungs is elevated to an abnormal level. This pressure increase puts stress upon the right heart side, which can end up which can lead to heart failure if not treated. While symptoms like fatigue and shortness of breath might be apparent however, the root causes that cause PH can be much more complex and are often unnoticed. Knowing the causes of PH is crucial to identify the problem early and provide effective treatment.

1. left-sided heart disease

The most prevalent causes of PH is left-sided heart disease. This can be caused by conditions like left-sided heart dysfunction, mitral valve disease or Aortic valve disease.

What causes it?

Left side of heart’s function is supplying oxygen-rich blood throughout the body. If it fails or weakens blood flows begin to come back into the lung. This can increase the pressure within the pulmonary veins and blood vessels, resulting in Pulmonary Hypertension as time passes.

Examples:

• Left ventricular systolic diastolic dysfunction

• Mitral valve stenosis, or regurgitation

• Aortic valve problems

What’s the significance?

This kind of PH is referred to by the term the Group 2 type of hypertension and is treated through the management of the underlying heart disease.

2. Lung Conditions with Chronic Low Oxygen levels

Long-term lung conditions are a major reason for PH. The conditions such as chronic obstructive Pulmonary Disease (COPD), interstitial lung disease along with sleep apnea cause persistently low levels of oxygen in blood.

How does it cause PH?

If the lungs aren’t getting enough oxygen The pulmonary arteries contract (tighten) this is which is known as hypoxic vasoconstriction. As time passes, this increases the pressure of blood in the lungs, ultimately cause PH.

Examples:

• COPD (Chronic bronchitis, Emphysema)

• Acute pulmonary fibrosis

• Obstructive sleep apnea

• Exposition to altitude for long durations

What is the significance of it:

This kind of condition is known as the Group 3 type of Hypertension and treatment of the lung disease is crucial for managing PH.

3. Chronic Lung Blood Clots (CTEPH)

Certain cases of PH can be due to chronic thromboembolic hypertension pulmonary (CTEPH)  one of the rare forms of PH caused by blood clots which do not dissolve.

What causes it?

Normally the body is able to break down clots within the lung. However, in CTEPH the clots persist and create scar tissue within the pulmonary arterial arteries. The arteries narrow or block the vessels, increasing pressure in the pulmonary circulation.

Risk factors:

• Deep vein thrombosis (DVT)

• The Pulmonary Embololism (PE)

• Clotting disorders

What is the significance of it:

It can be classified under group 4 PH. It is one of the few potentially curable forms of PH, often treated with surgery (pulmonary thromboendarterectomy).

4. The Pulmonary Arterial Hypertension (PAH) – Idiopathic or hereditary

Sometimes PH is not associated with any or underlying illness. This is referred to as Idiopathic PAH. In other instances it is inherited in families, and is referred to as heritable PAH.

What causes PH?

In these instances when this happens, it is possible that the blood vessels of the lungs can become ill and may get stiffer, thicker or get inflamed. This can reduce blood flow and increases the pressure inside the pulmonary arteries.

Possible triggers include:

• Gene-related mutations (especially BMPR2 gene)

• Unknown autoimmune conditions

• Hormonal imbalances

Why is it important:

It is also commonly referred to as the Group 1 type of hypertension and is treated using specific pulmonary vasodilator medication.

5. Congenital Heart Defects

A few people have structural defects within the heart like holes in the chambers (ASD or VSD) that can result in irregular blood flow between the lungs and the heart.

What causes it?

If oxygen-rich and oxygen-poor blood mixtures because of defects such as atrial septal defect (ASD) or the ventricular septal defect (VSD) The lung vessels receive a lot of blood. In time, this extra volume creates pressure in the pulmonary blood vessels.

Common defects:

• Patent ductus arteriosus (PDA)

• Atrial septal defect (ASD)

• Ventricular septal defect (VSD)

What is the significance of it:

It falls under the category of 1 (PAH caused by the congenital disease of the heart). In certain cases an early surgical intervention could stop PH from forming.

6. Liver Health (Porto pulmonary Hypertension)

Patients with severe liver diseases particularly cirrhosis might be diagnosed with PH in a condition referred to as porto pulmonary hypertension.

What causes it?

In cirrhosis, an insufficient blood flow through the liver can cause portal hypertension. This alters the flow of blood which causes blood vessels within the lungs to narrow and expand, resulting in the pressure in the lungs to increase.

Why is it important:

This is one of the subtypes of the PH Group 1. Liver transplantation can be beneficial however, patients must be stabilized prior surgery.

7. Connective Tissue Conditions

Autoimmune diseases, specifically systemtic Sclerosis (scleroderma) and Lupus are well-known to increase the chance for Pulmonary Hypertension.

How does it cause PH?

Inflammation causes damage to the blood vessel’s lining which causes fibrosis and narrowing of pulmonary blood vessels. Immune system’s assault against the body can cause constant inflammation as well as scarring on both lung tissue and blood vessels.

Examples:

• Systemic lupus erythematosus (SLE)

• Scleroderma

• Rheumatoid arthritis

Why is it important:

Patients who suffer from this condition fall into the category of Group 1. PAH and could require both immunosuppressants as well as PH-specific medications.

8. HIV Infection

While not very common, Pulmonary Hypertension can be an result from HIV infection even in patients with controlled viral load.

What causes it?

HIV is thought to trigger chronic inflammation, harm blood vessel linings and increase the risk of blood clotsand all of these could be a contributing factor to the formation of PAH.

Why is it important:

This is a different subtype of PAH Group 1 The early detection can improve outcomes when paired with antiretroviral treatment.

9. Utilization of Certain Drugs and Toxins

Certain medications and recreational substances have been implicated in the creation of PAH.

Common causes:

• Apetite-suppressants (e.g. Fenfluramine)

• Methamphetamines

• Cocaine

• Dasatinib (a cancer medication)

How does it cause PH?

The substances can directly harm blood vessels in the lungs or cause vasospasm, inflammation and vasospasm which can lead to damage over time and increased lung pressure.

Conclusion

The cause of pulmonary Hypertension cannot be a condition that has a single source of origin, it is it is a disorder that may be caused by several underlying diseases such as heart disease, lung issues as well as genetic changes, autoimmune disorders chronic clots and much more. Understanding the root cause is crucial since treatment options differ based upon the kind of PH being treated.

Although PH can be an “silent” disease at its earliest stages, the causes are a complex and extensive. Understanding the root causes of PH allows the patient and doctor to spot the disease in its early stages and select the most effective treatment option.

If you’re at risk of experiencing symptoms, talk to your physician to determine the cause of the pressure growing in your lungs.