Xerostomia is defined as "the subjective sensation of dryness of the mouth". It is common in patients with acute/chronic medical conditions, especially in patients with cancer. Results from observational studies reported 40% to 75% prevalence of xerostomia among cancer patients. Head and neck cancer patients, as the seventh most common type of cancer, reported an even higher prevalence (80%) of xerostomia after treatment compared with other cancer types. Despite the high prevalence of xerostomia, it is often underrecognized by patients and healthcare providers.

Xerostomia in head and neck cancer patients is largely induced by radiation in the head and neck region, which can damage salivary glands, and thereby change the volume, consistency, and pH of their saliva. Besides, xerostomia may be caused or exacerbated by the concomitant or sequential use of chemotherapy agents and other drugs (e.g., opioid). Consistent lacking saliva in cancer patients can lead to increased risk of oral fungal infection, caries, swallowing problems, sleep problems, depression, fatigue and altered taste, which may even result in poor nutritional status. Furthermore, xerostomia may become a chronic and even irreversible side effect.

Current therapies for xerostomia in cancer patients include both pharmacological and non-pharmacological treatments. Pharmacotherapy has been considered as a general treatment for stimulating saliva secretion in alleviating xerostomia for head and neck cancer patients. However, the evidence of pharmacological interventions (e.g., pilocarpine, bethanechol, amifostin, cevimeline and palifermin) on xerostomia is insufficient, and the use of pharmacotherapy may cause some common adverse effects, including nausea, sweating, nervousness, and urinary frequency. Non-pharmacological treatments such as saliva stimulants (e.g. citric and malic acids, chewing gum, toothpaste and lozenges) and saliva substitute (e.g. liquids, gels and sprays) have also been suggested to treat xerostomia, but neither with sufficient evidence of significant effect, and may also lead to adverse effects (e.g., nausea, unpleasant taste, diarrhea, and tooth mineralization). Some patients may find regular sips of water useful, but only for temporary benefit, because saliva is a complex substance with irreplaceable functions (antibacterial and immunologic protection). Therefore, an evidence-based effective strategy with few adverse events is warranted for head and neck cancer patients with xerostomia.

Both acupressure and acupuncture aim to improve health and cure illnesses by improving energy flow through stimulating meridian points. Acupressure is a non-invasive technique of activating acupoints using hands, fingers, or thumbs along the meridians, while acupuncture involves the use of needles. Stimulation on acupoints may increase the flow of blood and qi along the related meridians, as well as stimulate the local blood flow around the salivary glands, thereby increasing salivary secretion. Also, acupressure/acupuncture may stimulate the parasympathetic nervous system, hence indirectly stimulate salivary glands secretion. Besides, microcirculation may be promoted through the release of sensory neuropeptides, so as to increase the tissue oxygenation and metabolism. Some studies had demonstrated positive effect of acupuncture on xerostomia for head and neck cancer patients, while none examined acupressure. Based on the same meridian theory, both acupuncture and acupressure were widely applied to the symptom management (e.g. fatigue, nausea, pain) for cancer patients, effectively with good adherence. Compared to acupuncture, acupressure can be administered by patients themselves after training. The purpose of this study is to examine the effect of self-administered acupressure on xerostomia for head and neck cancer patients.