The U.S. Equal Employment Opportunity Commission recently adopted regulations implementing the ADA Amendments Act of 2008.
These regulations do not change the definition of "disability" but make it clear that the government will interpret the ADA more broadly than in the past. For the details, see "Final ADAAA Regulations Issued," in Nolo's Employment Law Blog.
If your small business has 15 or more employees, you are covered by the ADA and should take note of the new regulations. You may want to consider training your officers and managers to ensure that all of the company's decision-makers know that your employees might be considered to have a disability under the ADA, even if the disability is not immediately obvious.