Nasal congestion. This symptom occurs when the irritation from the allergy makes the nasal passages swell up. All of the swelling blocks the nose, making it hard for people to draw in a deep breath. Though it might seem obvious, it can actually be a little tricky to catch this symptom. Many dust mite allergies just breathe through their mouth without noticing that their nose feels stuffed up at all. However, others report that it can be quite uncomfortable. Some people may report that their nasal congestion makes their nose feel heavy or swollen. In some cases, the congestion is accompanied by a runny or dripping nose, but blowing out the mucous will not alleviate the congestion.
