WATCH: Sonia O'Sullivan joins pulmonary hypertension campaigners

Campaigners, including Sonia O'Sullivan, are raising awareness for pulmonary hypertension.

Pulmonary hypertension is a lung condition in which there is increased pressure in the pulmonary arteries that travel from the heart to the lungs.

"Pulmonary hypertension is a very rare disease. There are only about 300 patients in Ireland with PH. We are constantly trying to make people aware of it because often it can be mistaken for a less serious illness," explained Regina Prenderville from the Pulmonary Hypertension Association.

The Association is based in Mater University Hosptial, Dublin.

"I'm delighted to be here in Cobh to raise awareness for pulmonary hypertension," Ms O'Sullivan said.

The campaigners are hoping to inspire people to get active and get 'breathless' to raise awareness for the condition.

Ms O'Sullivan went to school with Christine Coakley, a PAH patient.