Overview: Sick building syndrome (SBS) describes a set of non-specific symptoms that occupants of a building may experience without an identifiable, single medical diagnosis. Symptoms are usually linked to time spent inside a particular building and often improve after leaving the space. Common complaints include headaches, eye, nose or throat irritation, fatigue, dizziness, skin irritation and difficulty concentrating. The phrase emphasizes a pattern of discomfort associated with the indoor environment rather than a clearly proven disease process.
Typical symptoms and how they present: Symptoms reported with SBS are varied and often subjective. They can be episodic or persistent while occupants remain in the building. Affected people may report nasal congestion, dry or itchy eyes, sore throats, exacerbation of allergy symptoms, unusual tiredness, and general malaise. Physical signs on medical testing are frequently absent or non-specific, which is why SBS is distinguished from diagnosable conditions that have confirmable causes.
Causes and contributing factors
- Poor ventilation and inadequate fresh-air exchange, including malfunctioning or poorly maintained HVAC systems.
- Contaminants from building materials and furnishings that release volatile organic compounds (VOCs) and other off-gassing chemicals.
- Biological contaminants such as mold, bacteria and pollen that develop where moisture accumulates; see mold resources for more details.
- Byproducts from office equipment (for example ozone from some copiers and printers) and from cleaning or industrial chemicals; learn about common ozone sources.
- Inadequate exhaust ventilation allowing recirculation of indoor pollutants; see guidance on ventilation standards.
Historical notes: Concern about health effects tied to building environments grew in the late 20th century as energy-efficient construction and air-tight buildings became more common. A World Health Organization report in 1984 highlighted the phenomenon and suggested that a substantial proportion of recently built or remodeled buildings reported occupant complaints, though estimates vary by study and location. For background on terminology and definitions see a general entry on syndrome and the original WHO report.
Prevention, mitigation and examples
Addressing SBS focuses on identifying and reducing sources of exposure and improving indoor air quality. Practical actions include: regular inspection and maintenance of heating, ventilation and air conditioning systems; increasing the rate of outdoor air exchange when feasible; choosing low-emitting construction and furnishing materials; controlling moisture to prevent mold growth; and substituting cleaning agents with lower-VOC formulations. Custodial policies can reduce risks by limiting the use of strong chemical cleaners and solvents—see guidance on safer products at cleaning products guidance.
Distinguishing SBS from related conditions and when to seek help: SBS refers to a collection of symptoms without a single identifiable cause; by contrast, "building-related illness" denotes specific clinically diagnosable conditions (for example, Legionnaires' disease) where a causal agent is established. When many occupants complain of similar symptoms, or if individuals develop more severe or persistent illness, employers and building managers should consult occupational health professionals or environmental health specialists for assessment, potential air sampling and targeted remediation. Practical standards such as filter ratings (e.g., MERV), localized exhaust, and occupant engagement in reporting problems can significantly reduce the prevalence of symptoms and improve wellbeing indoors.
For further reading and technical reference, consult authoritative public health and occupational guidelines and the linked resources above for more details on mold, ventilation, ozone sources, and safer cleaning practices.