The common cold is generally mild and self-limiting with most symptoms generally improving in a week. Half of cases go away in 10 days and 90% in 15 days. Severe complications, if they occur, are usually in the very old, the very young, or those who are immunosuppressed.
Types of sick sinus syndrome and their causes include: 1  Sinoatrial block. Electrical signals move too slowly through the sinus node, causing an abnormally slow heart rate. 2  Sinus arrest. The sinus node activity pauses.  Bradycardia-tachycardia syndrome.
Causes. Acute sinusitis is most often caused by the common cold, which is a viral infection. In some cases, a bacterial infection develops. Risk factors. You may be at increased risk of getting sinusitis if you have: Hay fever or another allergic condition that affects your sinuses