Cysts can arise through a variety of processes in the body, including.  1 wear and tear or simple obstructions to the flow of fluid, 2  infections, 3  tumors, 4  chronic inflammatory conditions, 5  genetic (inherited) conditions,  defects in developing organs in the embryo.
1 Acute * sinusitis often develops after a person has had a cold, with symptoms lasting less than 3 weeks. 2  Chronic * sinusitis can last 3 to 8 weeks or longer; it often occurs in people who have allergies or asthma. 3  Recurrent sinusitis consists of several acute episodes of sinusitis in 1 year.
Answer by Biophilia. Confidence votes 277. Viral infections differ in how long they are contagious. A viral cold may be contagious for seven to ten days; cold sores or genital herpes may be contagious throughout life during the time when an outbreak is present, just before an outbreak, or during symptoms.HIV is contagious throughout life.nswer by Biophilia. Confidence votes 277. Viral infections differ in how long they are contagious. A viral cold may be contagious for seven to ten days; cold sores or genital herpes may be contagious throughout life during the time when an outbreak is present, just before an outbreak, or during symptoms.