If you have had sinus inflammation for fewer than four weeks, you may have a condition known as acute sinusitis (sinus infection). Common symptoms include nasal congestion, facial pain, and drainage of a thick, yellow-to-green mucus. This condition is typically caused by a virus, but is sometimes caused by bacteria. Antibiotics are prescribed only when the infection is caused by bacteria.
What Is Acute Sinusitis?Sinusitis is a medical term used to describe inflammation (swelling and irritation) of the sinuses. Acute sinusitis is one type of sinusitis. It is diagnosed when symptoms have lasted for fewer than four weeks.
What Causes Acute Sinus Infections?Acute sinusitis is most often caused by a virus. This is known as acute viral sinusitis. Bacteria can also infect the sinuses, although this is less common. Bacteria cause up to 2 percent of acute sinus infections in adults and up to 13 percent in children (see Sinus Infections in Children).
Because infections are the main cause of sinusitis, the terms "sinusitis" and "sinus infection" often are used interchangeably.
Who Is at Risk?The sinuses are more likely to get infected in people with an upper respiratory infection, such as the common cold or flu. This is because the same viruses that cause upper respiratory infections also cause sinusitis.
Other things that can increase the risk for an acute sinus infection include:
- Allergies (i.e., hay fever or seasonal allergies)
- Infection of the ear or throat
- Swimming (chlorine can irritate the sinuses)
- Problems with mucus secretion or movement (such as in people with cystic fibrosis or primary ciliary dyskinesia)
- A weakened immune system
- Cocaine use
- Anything that partially or completely blocks the nose (such as a nasal polyp or deviated septum)
- Other factors that harm sinus drainage.
(Click Causes of Acute Sinusitis for more information on the specific causes of this condition.)