Small, singular polyps may cause no symptoms but a bunch of small polyps or larger ones blocking the sinus cavities and nasal passages may cause problems.

Symptoms of Nasal Polyps include:

• Nasally voice
• Mouth breathing in children is especially common as the nasal polyps block their small nasal
  passages and sinus cavities. Adults may also breathe through their mouths when large or
  multiple nasal polyps block these passages and spaces.
• Profuse nasal discharge (runny nose)
• Chronic nasal obstruction
• Persistent nasal stuffiness
• Chronic sinus infections. When Nasal polyps block sinus cavities and nasal passages they prevent the drainage of mucus from the sinus cavities. This leads to a build up of mucus in the sinus cavities, and provides an environment in which bacteria can thrive and multiply resulting in a sinus infection. Sinus Infections may recur if colds, flu's or allergies are left untreated.
• Headaches and Sinus pain
• Decreased sense of smell and taste. When nasal polyps obstruct the nasal passages they
  block aromas from reaching the sense receptors found in your nose. Ones sense of smell is directly related to their sense of taste. This means that a diminished ability to smell results
  in you loosing your ability to taste.
• Cold and flu symptoms that persist
• Blocked nasal passages as a result of nasal polyps may cause snoring.
• Large nasal polyps can alter the shape of your face. When nasal polyps grow larger than the sinus cavities/nasal passages in which they are found, a bulge can be seen on the surface of
  the persons face, altering the shape of their face.
• Post Nasal Drip
• Lack of sleep due to the various symptoms (above) felt when one has nasal polyps.