Heart failure is when the heart does not pump blood sufficiently. Dominating symptoms are shortness of breath, fatigue and peripheral oedema. The disease is serious and may result in considerable impairment of quality of life and has a high mortality. The prognosis is often poor but may be improved if the disease is early diagnosed and the medical management and pharmacotherapy is optimized. Natriuretic peptides are used as biomarkers for diagnosis and prognosis for heart failure. The peptide levels also mirror changes in the level of heart failure. To optimize the clinical outcome serial measurements of natriuretic peptides has been used as a therapeutic tool.