Chronic widespread pain (CWP) is considered one of the most common and costly health conditions today. Due to its complex aetiology, both psychopharmacological and psychosocial treatments have been struggling to lower pain intensity and disability in patients suffering from CWP. However, recent research has found that there is a strong association between low parasympathetic nervous system (PNS) activity and pain intensity in patients diagnosed with CWP. Furthermore, research has suggested that increasing PNS activity by stimulating the vagus nerve may lower pain intensity in patients with CWP. This present study will investigate and compare the effects of non-invasive transcutaneous vagal nerve stimulation (tVNS) and deep breathing (DB) on low PNS activity in patients with CWP. We hypothesise that by stimulating the vagal nerve, either exogenously with tVNS or endogenously with DB, we will increase PNS activity and therefore decrease pain intensity, disability, and increase both psycho and physiological wellbeing in patients suffering from CWP.