Pulmonary hypertension (PH) means the blood pressure in the arteries carrying blood from your heart to your lungs is too high. It's a different problem from ordinary "high blood pressure" (which affects the arteries feeding the rest of your body), and it's often a complication of another heart or lung condition rather than a stand-alone disease. Figuring out exactly which type you have is the single most important step, because the right treatment is completely different depending on the cause.
What Is Pulmonary Hypertension?
Normally, your heart's right side pumps blood to your lungs at fairly low pressure. In PH, something raises the resistance in the lung's blood vessels (or backs up pressure into them from the heart), forcing the right side of your heart to pump harder against that resistance — similar to how it's harder to push water uphill than downhill.
What's Happening in Your Heart and Lungs
The right ventricle isn't built like the left — it's thinner and used to lower-pressure work. When it's forced to work against sustained high pressure, it gradually thickens, then stretches and weakens, a process that can eventually lead to right-sided heart failure if the underlying cause isn't identified and treated. This is why early diagnosis matters more than the symptoms alone might suggest.
Types & Causes — The Five WHO Groups
Doctors classify PH into five groups, because treatment differs dramatically between them:
- Group 1 — Pulmonary Arterial Hypertension (PAH): the lung's blood vessels themselves are diseased and narrowed. Causes include idiopathic (no clear cause), hereditary forms, connective tissue diseases (like scleroderma or lupus), certain drugs/toxins, and congenital heart disease.
- Group 2 — Due to Left Heart Disease: the most common cause of PH overall. Heart failure (HFpEF — stiff, preserved contraction — or HFrEF — weak contraction) or valve disease raises pressure on the left side of the heart, which backs up into the lungs over time.
- Group 3 — Due to Lung Disease or Low Oxygen: COPD, pulmonary fibrosis, and untreated sleep apnea are common drivers.
- Group 4 — Chronic Thromboembolic PH (CTEPH): caused by old blood clots in the lung arteries that never fully dissolved. Notably, this type can sometimes be surgically treated — even potentially cured — which is exactly why ruling it in or out matters. (Full detail: Pulmonary Embolism (Acute & Chronic/CTEPH).)
- Group 5 — Unclear or Multiple Mechanisms: blood disorders, metabolic conditions, and other less common causes.
Common Symptoms
- Shortness of breath, especially with exertion, that often develops gradually
- Fatigue
- Swelling in the legs or ankles
- Chest pain or pressure
- Lightheadedness or fainting, particularly with activity
- Heart palpitations
- Bluish lips or fingertips in more advanced cases
How It's Diagnosed
An echocardiogram is usually the first test — it estimates lung artery pressure non-invasively. The definitive test is a right heart catheterization, which measures the actual pressures directly and is required to confirm the diagnosis and guide treatment. Finding the cause often involves lung function testing, a sleep study, a CT scan of the chest, a V/Q (ventilation-perfusion) scan to look specifically for old clots (Group 4), blood work, and a 6-minute walk test or CPET to measure your functional capacity. (See Cardiac Testing & Imaging and Procedures & Devices.)
Main Treatment Options
Treatment depends entirely on your group — there is no single "PH medication" that applies across all five:
- Group 1 (PAH) is treated with a specific family of medications that directly relax and open the lung's narrowed blood vessels, working through three main pathways: endothelin receptor antagonists, PDE5 inhibitors / guanylate cyclase stimulators, and prostacyclin pathway agents (available as pills, inhaled treatments, or continuous pump therapy for more advanced disease). (Full detail: Group 1 Pulmonary Hypertension Medications.) These are prescribed, titrated, and adjusted by a pulmonary hypertension specialist team — see "Who Does What on Your PH Team" below.
- Groups 2 and 3 are treated primarily by optimizing the underlying heart or lung disease — heart failure therapy, valve treatment, supplemental oxygen, or lung disease management — rather than the Group 1 PAH-specific medications above, which generally aren't used (and can sometimes be harmful) in Group 2 PH.
- Group 4 (CTEPH) may be treatable with a specialized surgery (pulmonary thromboendarterectomy) or a balloon procedure — potentially curative for the right candidate — alongside blood thinners, since old clots are the underlying cause.
- Group 5 treatment targets the underlying blood, metabolic, or other condition driving it.
- Supportive care across all groups can include supplemental oxygen if your blood oxygen is low, and diuretics if you're retaining fluid.
Who Does What on Your PH Team — the Cardiologist's Role
If you have Group 1 PAH, you'll likely notice you're being cared for by two specialists at once, and it helps to know why:
- Your pulmonary hypertension (pulmonology) specialist prescribes and titrates the PAH-specific medications above and manages the lung-vessel side of the disease.
- Your cardiologist's role is focused on your right heart — the chamber that has to do the extra work in PH. That means tracking, over time, how well the right ventricle is tolerating the elevated pressure: serial echocardiograms, periodic right heart catheterization to directly re-measure pressures, and — for some patients — a CardioMEMS sensor that allows daily pressure monitoring from home. Your cardiologist also manages fluid status, diuretics, and any right-sided heart failure symptoms that develop, and coordinates with pulmonology when a change in right heart function suggests the PAH treatment plan itself may need adjusting.
This isn't duplicated care — it's genuinely a two-specialty condition. Group 1 PAH is a disease of the lung's blood vessels and its consequence is a disease of the heart's right side, and each specialist is best positioned to manage a different half of that picture. For Groups 2–5, your cardiologist typically leads care directly, since the underlying driver is usually a heart (or heart-adjacent) condition to begin with.
Lifestyle Changes That Help
- Pace your activity — energy conservation techniques genuinely help day-to-day function
- Supervised exercise, once your PH team clears you, is often beneficial rather than something to avoid entirely
- Manage sodium and fluid similarly to heart failure guidance if you have fluid retention
- Get vaccinated against flu and pneumonia — respiratory infections are poorly tolerated with PH
- Avoid unpressurized high altitude and unplanned air travel without discussing oxygen needs with your team first
- Avoid stimulants and decongestants (see Medications & Substances to Avoid)
- If you're a woman of childbearing age with PAH, talk to your team about contraception — pregnancy carries significant risk with this specific condition and deserves a proactive conversation, not an assumption
Living With It / Outlook
Outlook varies enormously by which group you have — this is worth repeating because it's the single most important thing to understand about your own diagnosis. Group 2 and 3 PH often improves as the underlying heart or lung condition is treated. Group 1 (PAH) treatment has advanced significantly in recent decades, extending both survival and quality of life. Group 4 (CTEPH) is potentially curable with surgery in eligible patients. Ongoing follow-up with a PH specialist team is central to all of them.
When to Call Your Doctor vs. Go to the ER
- Increasing swelling or breathlessness with your usual activities
- Unexplained weight gain over a few days
- Severe shortness of breath at rest
- Chest pain or pressure
- Fainting or near-fainting
- Coughing up blood
Common Questions
Is this the same as regular high blood pressure?
No — they affect different blood vessels, are diagnosed differently, and are treated differently.
Will I need oxygen forever?
It depends on your group and how your condition responds to treatment — ask your PH team for your specific outlook.
Can this be cured?
Sometimes — Group 4 (CTEPH) can potentially be cured surgically. Other types are usually managed long-term rather than cured, but can often be controlled well.
Why did I need so many tests just to find the cause?
Because the five groups are treated completely differently — getting the classification right is what makes treatment work.
Why do I see both a cardiologist and a pulmonologist for this?
For Group 1 PAH specifically, it's genuinely a two-organ condition — your pulmonology specialist manages the lung-vessel disease itself while your cardiologist tracks how your right heart is tolerating the pressure, and the two coordinate rather than duplicate each other's work.