This method increases the volume of the nasal cavity and nasopharynx, leading to increased airflow and reduced respiratory arousals during sleep. See also

Airway resistance
Sleep apnea


== References ==
There are also congenital structural anomalies that can lead to constipation, including anterior displacement of the anus, imperforate anus, strictures, and small left colon syndrome. Pathophysiology
Diagnostic approach
The diagnosis is typically made based on a persons description of the symptoms. Bowel movements that are difficult to pass, very firm, or made up of small hard pellets (like those excreted by rabbits) qualify as constipation, even if they occur every day. Constipation is traditionally defined as three or fewer bowel movements per week. Other symptoms related to constipation can include bloating, distension, abdominal pain, headaches, a feeling of fatigue and nervous exhaustion, or a sense of incomplete emptying. Although constipation may be a diagnosis, it is typically viewed as a symptom that requires evaluation to discern a cause. Description
Distinguish between acute (days to weeks) or chronic (months to years) onset of constipation because this information changes the differential diagnosis. This in the context of accompanied symptoms helps physicians discover the cause of constipation. People often describe their constipation as bowel movements that are difficult to pass, firm stool with lumpy or hard consistency, and excessive straining during bowel movements. Bloating, abdominal distension, and abdominal pain often accompany constipation. Chronic constipation (symptoms present at least three days per month for more than three months) associated with abdominal discomfort is often diagnosed as irritable bowel syndrome (IBS) when no obvious cause is found.Poor dietary habits, previous abdominal surgeries, and certain medical conditions can contribute to constipation. Diseases associated with constipation include hypothyroidism, certain types of cancer, and irritable bowel syndrome.