The lungs

A serious and not uncommon symptom of APS is a blood clot in the lungs, known medically as a pulmonary embolism. Blood clots in the legs, arms or other parts of the body can break loose and travel to the lungs where the clot becomes known as a pulmonary embolism. This often stems from deep vein thrombosis (DVT).

DVT is one of the most common symptoms of APS and around one in ten people with untreated DVT will develop a pulmonary embolism.

The pulmonary embolism blocks the blood supply to the lungs and is a potentially life-threatening condition. The symptoms will depend on the size of the blood clot and may include:

• Shortness of breath
• Rapid breathing
• Light headedness
• Feelings of anxiety and nervousness
• Chest pain, which may be worse when you breathe in
• Coughing up blood
• Sudden collapse

It is very important to get treatment quickly as about 30% of people with untreated pulmonary embolism will die. The good news is that prompt diagnosis and treatment with anticoagulants can save lives and prevent further complications.

APS can also affect the lungs in other less common ways:

Pulmonary hypertension

This condition occurs due to abnormally high blood pressure in the arteries of the lungs.

The small arteries of the lung become narrowed and are unable to carry as much blood, causing pressure to build up. In APS, pulmonary hypertension is usually caused by recurrent blood clots in the lung (pulmonary emboli) and is quite rare, only affecting about 2-3% of patients.

Shortness of breath or light-headedness during activity is often the first symptom. Over time, symptoms can occur when the person is simply resting and can be accompanied by a fast heart rate. Other symptoms can include ankle and leg swelling, fainting spells, chest pain or pressure and fatigue. Many people with pulmonary hypertension find that their symptoms are inconsistent and they have good days and bad days.

The diagnosis of pulmonary hypertension should be confirmed by a specialist cardiologist, pulmonologist or rheumatologist. Although there is currently no known cure for pulmonary hypertension, anticoagulation treatment can prevent further pulmonary emboli and improve the outlook for patients. There are also a number of medications that can help treat the condition including supplementary oxygen and endothelin receptor antagonists.

Pulmonary haemorrhage

The lungs are full of millions of tiny, thin air sacs called alveoli that take care of the inhalation and exhalation of oxygen and carbon dioxide respectively. Haemorrhage (bleeding) into the alveoli can occasionally occur in APS patients, and symptoms can include coughing sometimes accompanied by blood, fever and shortness of breath. If left untreated, pulmonary haemorrhage can lead to respiratory failure and even death. Treatment usually starts with high doses of corticosteroids and needs very highly specialised care in hospital.