The sinuses are air-filled cavities in the bones of the face. They connect with the nose through narrow openings--and therein lies the rub. When the tissues lining the sinuses are inflamed, they swell and block the slender openings between the sinuses and the nose. The obstruction causes mucus accumulation creating sinus pressure and sometimes pain. If bacteria or fungi get into the sinuses while they are blocked, a sinus infection may occur. Sinus infections typically develop after a cold or the flu, although 5 percent to 10 percent of maxillary sinus infections are caused by dental infections.
Purulent Nasal Discharge
A sinus infection is typically accompanied by a purulent nasal discharge. Instead of the normally clear thin mucus, the discharge is thick and opaque. It is often yellow, green or grey. You may find it difficult to blow this thick mucus from your nose. You may also notice semisolid bits of dried mucus in the nasal discharge.
Postnasal Discharge and Sore Throat
The purulent discharge from a sinus infection often runs down the back of the throat, especially at night or while you are lying down. The flow of this discharge, often called postnasal drop, can cause a sore or scratchy throat.
Cough
The postnasal drip from a sinus infection frequently causes a persistent cough. The material that is coughed up appears the same as the nasal discharge because they are both coming from the same source. The cough is usually worse at night or while lying down because your position causes the sinus discharge to run down the back of the throat. The presence of other sinus infection symptoms points to the sinuses rather than the lungs as the source of the problem.
Bad Breath
A sinus infection often causes persistent bad breath, which is not improved by toothbrushing or other dental hygiene practices. The odor is caused by the presence of bacteria or fungi in the sinus discharge.
Altered Sense of Smell and Taste
The blocked nasal airflow that accompanies a sinus infection can cause a change in or a partial loss of your sense of smell. In addition, since the senses of taste and smell are interrelated, changes can occur in your sense of taste.
Headache and Facial Discomfort
The pressure created from blocked sinuses can cause headaches and facial discomfort. Facial discomfort can range from a feeling of pressure or fullness to tenderness and pain. These symptoms are localized to the sinuses involved in the infection. The cheeks, the area along the nose near the eyes, and the region along the brow line are commonly affected.
Tooth Pain
Infections of the maxillary sinuses of the cheekbones may cause referred pain, which is typically experienced as aching pain in the upper teeth. A clue that the problem is sinus-related and not a dental problem is the fact that the pain is diffuse and not localized to one or two teeth.
Fever
Fever may accompany a sinus infection, though this symptom is not uniformly present.
References
- "Principles and Practice of Infectious Diseases, Sixth Edition"; Gerald L. Mandell, M.D., John E. Bennett, M.D., Raphael Dolin, M.D., Editors; 2004
- "Harrison's Principles of Internal Medicine, 16th Edition"; Anthony S. Fauci, M.D., Eugene Braunwald, M.D., J. Larry Jameson, M.D., Ph.D., Dennis L. Kasper, M.D., Stephen L. Hauser, M.D., Dan L. Longo, M.D., Editors; 2004
- American Academy of Otolaryngology --- Head and Neck Surgery: Sinusitis
- American Academy of Allergy, Asthma and Immunology: Rhinitis and sinusitis
- Medline Plus: Sinusitis
