Pulmonary hypertension occurs when there is unusually high pressure inside the pulmonary circulation system. When pulmonary hypertension does not have an identifiable cause, it is called idiopathic pulmonary hypertension. Sometimes, the condition can be caused by drugs and diseases like dermatomyositis, scleroderma, and systemic lupus. Infections like HIV, liver and valvular diseases, congenital heart problems, COPD, and blood clots may also lead to pulmonary hypertension.

1. What are the symptoms of pulmonary hypertension?
People who have pulmonary hypertension (PH) may not have any apparent symptoms at all. This is particularly true when the disease is at an early stage. Otherwise, PH symptoms include shortness of breath, cough, dizziness, lethargy, fluid retention, causing swelling, chest pains, and angina, among others. The disease may have other manifestations too, depending on the underlying conditions it is associated with.

2. What conditions can become causes of pulmonary hypertension?
There can be multiple causes for PH, and usually, more than a single factor is involved in this disease. These factors also change how the disease progresses.

• Diseases, where blood circulation from the heart to the rest of the body is affected, can lead to a backflow of blood, elevating pulmonary venous pressures and causing PH.
• Hypoxic pulmonary vasoconstriction occurs when the lung vessels become narrow to divert the blood from the poorly-functioning parts of the lungs. For instance, if a person has pneumonia, a portion of his lung will be inflamed and does not perform lung functions well. So, this process will then divert blood from such poorly-working areas, sending it to the better-functioning tissues. A problem occurs if the blood has low-oxygen as it may lead to constriction of vessels and raise the pressure.
• In some diseases, the blood vessels are remodeled and the lumen or inner lining of vessels become narrow. It happens because of insufficient tissue growth within the vessel. Scarring from various diseases can also compress vessels and increase resistance to flow, leading to higher pressure.
• In a common infection called schistosomiasis, mainly occurring in Middle Eastern countries, blood vessels in the lungs get blocked because of parasites, causing pulmonary arterial hypertension.
• They are not commonly known causes of PH, but substances like anti-obesity medications may cause blood vessels to constrict. Most of these drugs have now been banned.
• Some diseases can elevated pulmonary pressure, resulting in PH. For instance, unknown toxins and chemicals can affect blood vessels by causing constrictions and inappropriate tissue growth around or inside the vessels. A condition called portal hypertension occurs because of liver failure.

3. Treatments
Treatments for PH will differ depending on its cause. For instance, for idiopathic or familial PH, the prognosis depends on how severe the condition is. In certain cases, there may be causes for poor prognosis too, like patient’s age(if it is beyond 45 years at the time of onset) or proof of right-sided heart failure. Patients who start treatment for idiopathic PH early can respond better to it.