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.
It is spread by direct contact with saliva and discharges from the nose or through airborne droplets from the upper respiratory tract of infected individuals. Mumps may be contagious seven days before and nine days after the onset of the disease. A person is most contagious 48 hours prior to the appearance of symptoms.The incubation period lasts two to three weeks. The virus multiplies in the mucous membranes of the nose and throat and then in regional lymph nodes.umps may be contagious seven days before and nine days after the onset of the disease. A person is most contagious 48 hours prior to the appearance of symptoms.