Allergies

• According to the the MedlinePlus website, "an allergen is something that triggers an reaction" and can be dependent on an individual's genes or environment. Allergies can cause many symptoms, including coughing, sneezing, sore throat, puffiness or itching of the eyes, fatigue and irritability, headaches and nasal congestion
  
  

Nasal congestion and sleep

• Allergies and snoring can be disruptful to a good night's sleep.Waking up image by mr.REP0RTER from Fotolia.com
  
  If the nasal passage is congested, it cannot take in sufficient air, causing the sleeper to resort to mouth breathing. According to the American Rhinologic Society, "when nasal congestion forces mouth-breathing during sleep, greater negative pressure develops behind the uvula and soft palate. This negative pressure increases the vibration of these 'noise-makers' during sleep, helping to create the sound we know as snoring."
  
  

Treatment

• Avoiding triggers that cause individuals' allergies can significantly reduce reactions. For people with strong allergic reactions, allergy medications such as antihistamines can alleviate congestion.