Means neither causing nor exhibiting symptoms of disease. Symptomatic means a physical indication (rash, pain, discomfort etc.) of disease or disorder. For example, red spots are symptomatic of measles and chest pain is symptomatic of a heart attack (myocardial infarction). Do not confuse "symptomatic" with the term systemic, which means spread throughout the body. Additional Info: Many diseases or conditions do not display any symptoms and are therefore asymptomatic. For example, a cerebral aneurysm may not show any symptoms until it ruptures, at which point the symptoms become immediately evident. Most small cancers are asymptomatic until they reach an appreciable size. In terms of occupational exposures, a chemical can have delayed effects on the body, so your exposure may initially be asymptomatic. One example is inhalation of asbestos fibers - the symptoms of the lung damage may not show up for years. Another example is skin exposure to hydrofluoric acid, which usually causes no initial pain, but over hours or days can reveal itself through excruciating pain, physical damage and/or death. Just because one does not display symptoms of a disease or chemical exposure does not necessarily mean that one does not have the disease or was not exposed. Certain symptoms might occur only 50% of the time...or not at all depending on the individual involved. In general, being asymptomatic is a good thing, but it is not a guarantee of health. Be alert for unusual changes in your health at all times, but particularly whenever you work with hazardous materials. MSDS Relevance: "Asymptomatic" usually appears on an MSDS in the context of an exposure to the material not causing any obvious symptoms even though it presents a health hazard. This is why it is always important to read and understand MSDS's before working with workplace substances. "Symptomatic" usually appears in reference to the recommended treatment for exposure to the material. For example, the MSDS may say to treat the effects by treating the symptoms it causes (e.g. "treat symptomatically"). That means while you can't treat the exposure directly, you can mitigate its effects by giving ibuprofen for pain, oxygen for breathing difficulty etc. When reading and understanding MSDS's, be sure to take in the Big Picture. Many different processes can cause the same set of symptoms. For example, chest pain is symptomatic of a heart attack, but it also indicates a bad case of heart burn. Just because you are showing symptoms of exposure to a material, do not immediately rule out other likely causes. If you have the slightest doubt about the cause of a symptom, consult your physician or hospital emergency room. See also: Inhalation