For the majority of persons with CFS, work, school, and family activities are significantly reduced for extended periods of time. The severity of symptoms and disability is the same regardless of gender, and many experience strongly disabling chronic pain. Persons report critical reductions in levels of physical activity. Also, a reduction in the complexity of activity has been observed. Reported impairment is comparable to other fatiguing medical conditions including late-stage AIDS, lupus, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), and end-stage kidney disease. CFS affects a persons functional status and well-being more than major medical conditions such as multiple sclerosis, congestive heart failure, or type II diabetes mellitus.Often, courses of remission and relapse of symptoms occur, which make the illness difficult to manage. Persons who feel better for a period may overextend their activities, and the result can be a worsening of their symptoms with a relapse of the illness.About 25% of people with CFS are house-bound or bed-ridden for long periods during their illness, often for decades. : 32  An estimated 75% are unable to work because of their illness. More than half were on disability benefits or temporary sick leave, and less than a fifth worked full-time. Children who become ill with CFS are a major cause of school absence.
Sinus may refer to:

Anatomy
Sinus (anatomy), a sac or cavity in any organ or tissue
Paranasal sinuses, air cavities in the cranial bones, especially those near the nose, including:
Maxillary sinus, is the largest of the paranasal sinuses, under the eyes, in the maxillary bones
Frontal sinus, superior to the eyes, in the frontal bone, which forms the hard part of the forehead
Ethmoid sinus, formed from several discrete air cells within the ethmoid bone between the eyes and under the nose
Sphenoidal sinus, in the sphenoid bone at the center of the skull base under the pituitary gland
Anal sinuses, the furrows which separate the columns in the rectum
Dural venous sinuses, venous channels found between layers of dura mater in the brain
Sinus (botany), a space or indentation, usually on a leaf

Heart
Sinus node, a structure in the superior part of the right atrium
Sinus rhythm, normal beating on an ECG
Coronary sinus, a vein collecting blood from the heart
Sinus venosus, a cavity in the heart of embryos
Sinus venarum, a part of the wall of the right atrium in adults, developed from the sinus venosus

Other uses
Sinus (Chalcidice), a town of ancient Chalcidice, Greece
Sinus, gulf or bay in Latin, used in numerous toponyms in ancient writing (e.g., Sinus Magnus, Sinus Flanaticus, etc.) Sine, a trigonometric math function (Latin sinus)

See also
Sinus Medii, a small lunar mare
Sinus Successus, a lunar feature
Sines, a municipality in Alentejo, Portugal (Latin Sinus)
Sinusitis, a common ailment resulting in the inflammation of the paranasal sinuses