PH Central - Features medical information, support options, news, events, research, forums and mailing lists, legislative action center, and personal pages.
PPH Cure Foundation - A non-governmental funder of medical research into the causes of and therapies for primary pulmonary hypertension. Includes background information, research articles, clinical trials, and patient stories.
Primary Pulmonary Hypertension - National Institute of Health pamphlet covering the incidence, symptoms, cause, diagnosis, and treatment of the disease. Available in HTML, PDF, and print format.
Primary Pulmonary Hypertension (PPH) e. V. - Non-profit self help and support association. Includes background information and contact details. [Information in English and German]
Priority Healthcare Corporation - Pulmonary hypertension information covering symptoms as well as primary and secondary pulmonary hypertension.
Pulmonary Hypertension Association - Features association background, disease and treatment information, news, research, and message boards.