Definition

Pressure helps blood flow through blood vessels. Hypertension occurs when this pressure gets too high. When this happens in the blood vessels in the lungs it is called pulmonary hypertension.

Normal pressure for blood flow through the lungs is one-sixth of the pressure for the rest of the body. Pressure may rise for any number of reasons. It creates a potentially serious condition. The right side of the heart needs to pump harder to move blood against the pressure. If left untreated the right side of the heart can eventually fail.

Pulmonary Circulation

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Causes

The blood vessels in the lungs are very sensitive to oxygen. The lower the level of oxygen, the narrower the vessels become. Higher pressure will be needed to push blood through the narrow blood vessels. Pressure will also increase when there is more blood in the lungs than normal.

These situations may be caused by:

    
  • Chronic obstructive pulmonary disease (COPD) is the most common cause. This condition causes destruction of lung tissue. This decreases the number of blood vessels. It also lowers the amount of oxygen available.     
  • COPD is a combination of chronic bronchitis and emphysema
  • Usually due to years of tobacco damage
  • Heart abnormalities can result in extra blood in the lungs. Some are conditions people are born with. Others may develop over time. Some of these conditions are:     
  • Septal defects (holes between the right and left sides of the heart, present at birth)
  • Tight (stenotic) or leaky heart valves
  • Some lung diseases scar the lungs. This makes them less flexible.     
  • Scleroderma (systemic sclerosis)—stiffen blood vessels, effectively preventing them from opening which raises the pressure
  • Patients who have large sections of lung removed surgically
  • Systemic lupus erythematous
  • In obstructive sleep apnea breathing stops at times through the night. This lowers available oxygen. As a result, pulmonary blood pressure will also increase.
  • Muscle weakness can make it difficult to breathe. This will lower the available oxygen. This weakness is common in neuromuscular disorders such as:     
  • Polio
  • ALS
  • Myasthenia gravis
  • Mountain climbers all develop the condition. It is the natural result of breathing thin air. This is one cause of high altitude sickness.
  • Pulmonary embolism is a build up of blood clots in the lungs. These clots plug up the blood vessels.
  • A type of chest wall deformity is known as pectus excavatum. Rarely, severe scarring of the chest wall, can prevent chest expansion. It has the same effect as scarring of the lungs themselves.
  • Idiopathic pulmonary arterial hypertension is due to defects in the arteries of the lungs. There is no known cause. It is likely due to genetic factors.

    • Other factors and conditions that can create pulmonary hypertension include:

        
  • Exposure to certain substances, such as cocaine and amphetamines
  • HIV positive status
  • Liver disease

    • Risk Factors

    The following factors increase your chance of developing this condition:

        
  • Smoking
  • Asthma or other chronic lung disease
  • Recurring pulmonary emboli
  • Obstructive sleep apnea
  • Obesity
  • Low thyroid (myxedema)
  • Certain congenital and valvular heart conditions
  • Muscle weakness diseases
  • Home at high altitude (over 10,000 feet)
  • Pectus excavatum or other severe chest deformity (eg, kyphoscoliosis)

    • Symptoms

    If you have any of these, see your doctor. They suggest a condition that may need medical attention.

        
  • Progressive shortness of breath
  • Chronic cough
  • Chronic fatigue
  • Fainting spells
  • Ankle swelling from fluid retention
  • Heart pain ( angina )

    • Diagnosis

    Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to a specialist in heart or lung diseases. A cardiologist focuses on the heart. A pulmonologist focuses on the lungs.

    Tests may include the following:

        
  • Blood gas determination
  • Cardiac catheterization
  • Pulmonary function test
  • Computerized axial tomography (CAT) scan
  • Echocardiogram

    • Treatment

    Most cases of pulmonary hypertension are due to another disease. In this case the underlying cause is treated.

    For some, no treatable cause is found. In this case, there are several medications that might be of benefit. Talk with your doctor about the best plan for you. Treatment options include the following:

    Medications

        
  • Calcium channel blockers
  • Anticoagulants
  • Diuretics
  • Oxygen
  • Phosphodiesterase inhibitors ( sildenafil )
  • Prostacyclin ( epoprostenol , iloprost )—These must be administered by continuous infusion either intravenously, subcutaneously, or by inhalation.
  • Endothelin receptor blockers ( bosentan )

    • Lung Transplantation

    This is a drastic treatment. It is only recommended for life-threatening disease.

    Prevention

    To help reduce your chances of getting pulmonary hypertension, take the following steps:

        
  • Do not smoke
  • Control asthma effectively
  • Maintain proper weight
  • Treat conditions that can lead to pulmonary hypertension