This chapter addresses the fundamental nursing in managing breathlessness. Every nurse should possess the knowledge and skills to assess patients holistically, to select and implement evidence-based strategies, to manage breathlessness, and to review the effectiveness of these to inform any necessary changes in care. The nurse has a key role in managing this often frightening symptom, which may be caused by many disorders, including certain heart and respiratory conditions, strenuous exercise, or anxiety. Breathlessness is described as a distressing subjective sensation of uncomfortable breathing (Mosby, 2009) and can be expressed as an unpleasant or uncomfortable awareness of breathing, or of the need to breathe (Gift, 1990). The term dyspnoea, also meaning breathlessness, is derived from the Greek word for difficulty in breathing. Whilst it is difficult to estimate the prevalence of dyspnoea, it is apparent when we exercise beyond our normal tolerance levels; pathologically, dyspnoea occurs with little or no exertion and is a symptom response to different aetiologies (causes of illness). Breathlessness is a common symptom in patients with both cardiac (McCarthy et al., 1996) and respiratory disease (Dean, 2008), and also in people with neuromuscular diseases approaching the end of life; this can prove difficult and distressing to manage (see Chapter 18 Managing End-of-Life Care). There is a peak incidence of chronic dyspnoea in the 55–69 age group (Karnani, 2005), and the prevalence and severity of dyspnoea increases with age. This is associated with an increase in mortality and reduction in quality of life (Huijnen et al., 2006). It is estimated that 70% of all terminal cancer patients experience breathlessness in their last 6 weeks of life (Davis, 1997). Both physiological and psychological responses (including pain, emotion, and anxiety) can lead to an increase in respiratory rate. Breathing is controlled by the respiratory centre in the medulla of the brain. Higher centres in the cerebral hemispheres can voluntarily control respiratory rate so that breathing can be temporarily stopped, slowed, or increased. The respiratory centre generates the basic rhythm of breathing, with the depth and rate being altered in response to the body’s requirements, mainly by nervous and chemical control (Ward and Linden, 2008).