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.
Acute sinusitis can be caused by viral, bacterial, or fungal infections. Allergans and environmental irritants are other possible causes. In most cases, acute sinusitis is caused by an upper respiratory tract viral infection, such as the common cold, and usually resolves on its own.